diff --git a/ALPS3_MIGRATION_PLAN.md b/ALPS3_MIGRATION_PLAN.md
index f2a81fe..d36dd4d 100644
--- a/ALPS3_MIGRATION_PLAN.md
+++ b/ALPS3_MIGRATION_PLAN.md
@@ -223,9 +223,11 @@ Measured facts that the design relies on:
 | Targeted cases | Covariance (text, HDF5); `DATA_IN_HDF5`; `X_i`/`SIGMA_i` input; explicit `TAU_i`; T=0, time-bosonic, anomalous (PH and non-PH) kernels; every default model incl. tabulated; every grid; `MODEL_RUNS` (varspec) | same, plus a component harness that dumps the kernel matrix, its singular values, the grid and the discretized default model for small sizes |
 | CLI snapshots | `--help`, `--help.models`, `--help.grids`, missing-parameter error | exact text (exit codes once B1 is fixed) |
 
+`GENERATE_ERR` is covered by `t_generate_err`; its bootstrap output is
+reproducible because `SEED` defaults to 0 (B10).
+
 Not captured:
 
-* `GENERATE_ERR`: seeded from the clock (B10). It gets a reference after the seed parameter is added.
 * The LAPACK SVD path: compared against the Eigen results within tolerance, with no separate reference.
 
 Cases that run through suspected bugs record current behavior and are flagged
@@ -406,20 +408,29 @@ need careful checking at large l and argument) and `program_options` (no
 standard equivalent). Reconfirmed 2026-09-24: these are intentional retained
 Boost boundaries for now.
 
-**2.3C: command-line behavior** (updates the CLI references on purpose)
-
-* B1: non-zero exit code on errors, together with `boost::diagnostic_information`
-  → `e.what()` (moved here from 2.2).
-* B16: accept `half-lorentzian` as well as `half lorentzian`, and show the real
-  `CUT` default in `--help.grids`.
-* B10: a `SEED` parameter for the bootstrap errors (moved here from 2.2).
-
-**2.3D: numerical changes** (each its own commit and `REFERENCE_CHANGES.md` entry)
-
-* B7b: time-bosonic kernel: use the ω→0 limit only at ω = 0.
-* B15: remove the `float` casts in the log grid.
-* B11 (optional): `BDCSVD` instead of `JacobiSVD`; measure against the
-  references before deciding.
+**2.3C: command-line behavior — Done 2026-09-24** (updates the CLI references on purpose)
+
+* **Done 2026-09-24:** B1: non-zero exit code on errors, together with
+  `boost::diagnostic_information` → `e.what()` (moved here from 2.2).
+* **Done 2026-09-24:** B16: accept `half-lorentzian` as well as
+  `half lorentzian`, and show the real `CUT` default in `--help.grids`.
+* **Done 2026-09-24:** B10: a `SEED` parameter for the bootstrap errors,
+  defaulting to 0 for reproducibility (moved here from 2.2). Added the
+  `t_generate_err` regression reference for the deterministic default and
+  `t_generate_err_seed` to verify that an explicit non-default seed is used.
+
+**2.3D: numerical changes — Done 2026-09-24** (each accepted change its own
+commit and `REFERENCE_CHANGES.md` entry)
+
+* **Done 2026-09-24:** B7b: time-bosonic kernel uses the ω→0 limit only
+  at ω = 0. Updated the targeted and component references.
+* **Done 2026-09-24:** B15: replaced the log-grid `float` casts with explicit
+  `double` conversions. Existing grids are bit-identical (the integer values
+  used by the tests and normal runs are exactly representable as `float`).
+* **Measured 2026-09-24; keep `JacobiSVD`:** `BDCSVD` did not improve the
+  large Legendre case (57.49 s, effectively unchanged), while its different
+  singular vectors changed the deterministic bootstrap-error result by about
+  3%. The optional B11 change therefore has no demonstrated benefit here.
 
 Keep the `MaxEntSimulation` public getters stable, because the tests use them.
 
diff --git a/src/maxent.cpp b/src/maxent.cpp
index 8d4639a..5fdba78 100644
--- a/src/maxent.cpp
+++ b/src/maxent.cpp
@@ -11,11 +11,11 @@
 
 #include "maxent.hpp"
 #include <alps/utilities/fs/remove_extensions.hpp>
-#include <boost/exception/diagnostic_information.hpp> 
 
 
 int main(int argc,const char** argv)
 {
+  try {
   alps::params parms(argc,argv); 
   MaxEntSimulation::define_parameters(parms);
   //other help messages
@@ -62,8 +62,8 @@ int main(int argc,const char** argv)
     std::cout << "For more information see examples/grids.pdf\n"              << std::endl;
     std::cout <<std::left << std::setw(15)<< "Grid Name"      <<'\t' << "option=default" << std::endl;
     std::cout <<std::left << std::setw(15)<< "========="      <<'\t' << "==============" << std::endl;
-    std::cout <<std::left << std::setw(15)<< "lorentzian"     <<'\t' << "CUT=0.1" << "\n"
-              <<std::left << std::setw(15)<< "half-lorentzian"<<'\t' << "CUT=0.1" << "\n"
+    std::cout <<std::left << std::setw(15)<< "lorentzian"     <<'\t' << "CUT=0.01" << "\n"
+              <<std::left << std::setw(15)<< "half-lorentzian"<<'\t' << "CUT=0.01" << "\n"
               <<std::left << std::setw(15)<< "quadratic"      <<'\t' << "SPREAD=4" << "\n"
               <<std::left << std::setw(15)<< "log"            <<'\t' << "LOG_MIN=0.0001" << "\n"
               <<std::left << std::setw(15)<< "linear"         <<'\t' << "---" << std::endl;
@@ -95,7 +95,6 @@ int main(int argc,const char** argv)
   else
     basename=parms["BASENAME"].as<std::string>();
   
-  try{
         if(exitEarly){
           throw std::runtime_error("Critical parameters not defined");
         }
@@ -163,11 +162,14 @@ int main(int argc,const char** argv)
           my_sim.run();
           my_sim.evaluate();
         }
+    return 0;
   }
     catch(const std::exception &e){
-        std::cerr << "Caught Exception " << boost::diagnostic_information(e);
+        std::cerr << "Caught Exception: " << e.what() << '\n';
+        return 1;
     }
     catch(...){
-        std::cerr << "Caught Exception" << boost::current_exception_diagnostic_information();
+        std::cerr << "Caught Exception: unknown exception\n";
+        return 1;
     }
 }
diff --git a/src/maxent.hpp b/src/maxent.hpp
index fb4bf39..1df6877 100644
--- a/src/maxent.hpp
+++ b/src/maxent.hpp
@@ -70,6 +70,7 @@ public :
   void generateCovariantErr(const vector_type& A_in, const double alpha, ofstream_ &os);
 
 private:
+  std::mt19937::result_type bootstrap_seed_;
   ///discretized and normalized version of the default model.
   vector_type def_;
   ///check that the default model is non-zero
diff --git a/src/maxent_grid.cpp b/src/maxent_grid.cpp
index 30b96b5..5f7f973 100644
--- a/src/maxent_grid.cpp
+++ b/src/maxent_grid.cpp
@@ -22,7 +22,7 @@ t_array_(nfreq_+1){
   if (p_f_grid =="lorentzian") {
     initialize_lorentzian_grid(cut);
   }
-  else if (p_f_grid=="half lorentzian") {
+  else if (p_f_grid=="half lorentzian" || p_f_grid=="half-lorentzian") {
     initialize_half_lorentzian_grid(cut);
   }
   else if (p_f_grid=="quadratic") {
@@ -46,18 +46,18 @@ void grid::initialize_linear_grid() {
 
 void grid::initialize_logarithmic_grid(double t_min) {
   double  t_max = 0.5;
-  double scale = std::log(t_max / t_min) / ((float) ((nfreq_ / 2 - 1)));
+  double scale = std::log(t_max / t_min) / static_cast<double>(nfreq_ / 2 - 1);
   t_array_[nfreq_ / 2] = 0.5;
   for (int i = 0; i < nfreq_ / 2; ++i) {
     t_array_[nfreq_ / 2 + i + 1] = 0.5
-        + t_min * std::exp(((float) (i)) * scale);
+        + t_min * std::exp(static_cast<double>(i) * scale);
     t_array_[nfreq_ / 2 - i - 1] = 0.5
-        - t_min * std::exp(((float) (i)) * scale);
+        - t_min * std::exp(static_cast<double>(i) * scale);
   }
   //if we have an odd # of frequencies, this catches the last element
   if (nfreq_ % 2 != 0)
     t_array_[nfreq_ / 2 + nfreq_ / 2 + 1] = 0.5
-    + t_min * std::exp(((float) (nfreq_) / 2) * scale);
+    + t_min * std::exp(static_cast<double>(nfreq_) / 2 * scale);
 }
 
 void grid::initialize_quadratic_grid(double spread) {
@@ -100,5 +100,3 @@ void grid::initialize_lorentzian_grid(double cut) {
 }
 
 
-
-
diff --git a/src/maxent_helper.cpp b/src/maxent_helper.cpp
index 78f2624..406a8ad 100644
--- a/src/maxent_helper.cpp
+++ b/src/maxent_helper.cpp
@@ -11,7 +11,6 @@
 
 #include "maxent.hpp"
 #include <cmath>
-#include <ctime>
 #include <Eigen/Eigenvalues>
 #include <Eigen/Cholesky>
 #include "maxent_backcont.hpp"
@@ -21,7 +20,9 @@
 //NOTE: size1= rows; size2=columns
 
 MaxEntHelper::MaxEntHelper(alps::params& p) :
-MaxEntParameters(p) , def_(nfreq()), text_output(p["TEXT_OUTPUT"])
+MaxEntParameters(p),
+bootstrap_seed_(p["SEED"].as<std::mt19937::result_type>()),
+def_(nfreq()), text_output(p["TEXT_OUTPUT"])
 {
     for (int i=0; i<nfreq(); ++i)
         def_[i] = MaxEntParameters::Default().D(omega_coord(i)) * delta_omega(i);
@@ -355,8 +356,7 @@ void MaxEntHelper::generateCovariantErr(const vector_type& A, const double alpha
       A_u(i) = sqrt(A(i));
     A_u = u*A_u;
 
-    std::mt19937 rng;
-    rng.seed(static_cast<unsigned int>(std::time(0)));
+    std::mt19937 rng(bootstrap_seed_);
 
     std::vector<vector_type> noise_vecs;
     int max_it = 10000;
diff --git a/src/maxent_kernel.cpp b/src/maxent_kernel.cpp
index b5ec5c6..3e782c2 100644
--- a/src/maxent_kernel.cpp
+++ b/src/maxent_kernel.cpp
@@ -79,10 +79,10 @@ K_(ndat_,nfreq_)
     else if (ktype_==time_bosonic_kernel) {
       for (int i=0; i<ndat_; ++i) {
         double tau=tau_points_[i];
-        K_(i,0) = T_;
-        for (int j=1; j<nfreq_; ++j) {
+        for (int j=0; j<nfreq_; ++j) {
           double omega = freq[j];
-          K_(i,j) = 0.5*omega * (std::exp(-omega*tau) + std::exp(-omega*(1./T_-tau))) / (1 - std::exp(-omega/T_));
+          K_(i,j) = omega == 0.0 ? T_ :
+            0.5*omega * (std::exp(-omega*tau) + std::exp(-omega*(1./T_-tau))) / (1 - std::exp(-omega/T_));
           if(std::isnan(K_(i,j))) K_(i,j)=0; //the limit of the function above for omega -> -Infity
         }
       }
diff --git a/src/maxent_simulation.cpp b/src/maxent_simulation.cpp
index 5282782..0e761c5 100644
--- a/src/maxent_simulation.cpp
+++ b/src/maxent_simulation.cpp
@@ -56,6 +56,7 @@ void MaxEntSimulation::define_parameters(alps::params &p){
   p.define<double>("NORM",1.0,"NORM");
   p.define<bool>("BACKCONTINUE",true,"Output A(omega) back to imaginary axis");
   p.define<bool>("GENERATE_ERR",false,"Generate a bootstrap approximation for error bars");
+  p.define<unsigned int>("SEED",0,"Seed for reproducible bootstrap error bars");
   //*********************************
   p.define<double>("BETA","beta, inverse temperature");
   p.define<int>("NDAT","# of input points");
diff --git a/test/gridTest.cpp b/test/gridTest.cpp
index 16d3563..c0815cf 100644
--- a/test/gridTest.cpp
+++ b/test/gridTest.cpp
@@ -104,7 +104,21 @@ TEST(Grid,HalfLorentzianEven){
     
     grid g(p);
     EXPECT_EQ(g(0),0);
-    EXPECT_EQ(g(NFREQ),1);
+  EXPECT_EQ(g(NFREQ),1);
+}
+TEST(Grid,HalfLorentzianHyphenAlias){
+    alps::params p;
+    MaxEntSimulation::define_parameters(p);
+    const int NFREQ=20;
+    p["NFREQ"] = NFREQ;
+
+    p["FREQUENCY_GRID"] = "half lorentzian";
+    grid spaced(p);
+    p["FREQUENCY_GRID"] = "half-lorentzian";
+    grid hyphenated(p);
+
+    for(int i=0;i<=NFREQ;i++)
+      EXPECT_EQ(hyphenated(i),spaced(i));
 }
 TEST(Grid,QuadraticEven){
     alps::params p;
@@ -147,4 +161,3 @@ TEST(Grid,LinearEven){
 }
 
 
-
diff --git a/test/regression/CMakeLists.txt b/test/regression/CMakeLists.txt
index 97e109b..8882557 100644
--- a/test/regression/CMakeLists.txt
+++ b/test/regression/CMakeLists.txt
@@ -27,6 +27,10 @@ if(NOT have_python_modules)
   return()
 endif()
 
+add_test(NAME regression_harness_unit
+  COMMAND ${Python3_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test_generate.py)
+set_tests_properties(regression_harness_unit PROPERTIES LABELS unit)
+
 function(maxent_regression_test name sets label)
   set(results ${CMAKE_CURRENT_BINARY_DIR}/results-${name})
   add_test(NAME regression_${name}_generate
diff --git a/test/regression/MANIFEST.md b/test/regression/MANIFEST.md
index 5a3fd03..14a139e 100644
--- a/test/regression/MANIFEST.md
+++ b/test/regression/MANIFEST.md
@@ -24,7 +24,9 @@ Generated by `manifest.py` from `reference/`, `cases.py` and `tolerances.json`.
 |---|---|---|---|---|---|
 | `t_cov_hdf5` | DATA_IN_HDF5 with /Covariance, frequency PH | `test/regression/inputs/t_cov_hdf5` | 20 | 0.1 s |  |
 | `t_cov_text` | covariance matrix from text file, time fermionic | `test/regression/inputs/t_cov_text` | 20 | 0.1 s |  |
-| `t_grid_half_lorentzian` | grid: half lorentzian | `test/regression/inputs/t_grid_half_lorentzian` | 20 | 0.1 s | B16 (help text says 'half-lorentzian') |
+| `t_generate_err` | bootstrap error bars with the default SEED=0 | `test/regression/inputs/t_generate_err` | 21 | 0.0 s |  |
+| `t_generate_err_seed` | bootstrap error bars with explicit SEED=1234 | `test/regression/inputs/t_generate_err_seed` | 21 | 0.1 s |  |
+| `t_grid_half_lorentzian` | grid: half-lorentzian alias | `test/regression/inputs/t_grid_half_lorentzian` | 20 | 0.1 s |  |
 | `t_grid_linear` | grid: linear | `test/regression/inputs/t_grid_linear` | 20 | 0.1 s |  |
 | `t_grid_log` | grid: log | `test/regression/inputs/t_grid_log` | 20 | 0.1 s |  |
 | `t_grid_lorentzian` | grid: lorentzian | `test/regression/inputs/t_grid_lorentzian` | 20 | 0.1 s |  |
@@ -33,7 +35,7 @@ Generated by `manifest.py` from `reference/`, `cases.py` and `tolerances.json`.
 | `t_kernel_anomalous_nonph` | anomalous kernel, frequency non-PH | `test/regression/inputs/t_kernel_anomalous_nonph` | 24 | 0.1 s |  |
 | `t_kernel_anomalous_ph` | anomalous kernel, frequency PH | `test/regression/inputs/t_kernel_anomalous_ph` | 24 | 0.1 s |  |
 | `t_kernel_legendre_bosonic` | Legendre bosonic kernel | `test/regression/inputs/t_kernel_legendre_bosonic` | 24 | 0.1 s | B17 (Legendre bosonic uses the fermionic integrand) |
-| `t_kernel_time_bosonic` | time bosonic kernel, OMEGA_MIN=0 | `test/regression/inputs/t_kernel_time_bosonic` | 24 | 0.1 s | B7 (fixed; K(i,0)=T assumes the grid starts at 0) |
+| `t_kernel_time_bosonic` | time bosonic kernel, OMEGA_MIN=0 | `test/regression/inputs/t_kernel_time_bosonic` | 24 | 0.3 s |  |
 | `t_kernel_tzero` | T=0 kernel, OMEGA_MIN=0 | `test/regression/inputs/t_kernel_tzero` | 20 | 0.1 s |  |
 | `t_model_double_gaussian` | default model: double gaussian | `test/regression/inputs/t_model_double_gaussian` | 20 | 0.1 s |  |
 | `t_model_double_lorentzian` | default model: double lorentzian | `test/regression/inputs/t_model_double_lorentzian` | 20 | 0.1 s |  |
@@ -57,9 +59,9 @@ Generated by `manifest.py` from `reference/`, `cases.py` and `tolerances.json`.
 | Case | Covers | Inputs | Datasets | Runtime | Flags |
 |---|---|---|---|---|---|
 | `cli_help` | --help output (`--help`) | none | 8 | 0.0 s |  |
-| `cli_help_grids` | --help.grids output (`--help.grids`) | none | 8 | 0.0 s | B16 |
+| `cli_help_grids` | --help.grids output (`--help.grids`) | none | 8 | 0.0 s |  |
 | `cli_help_models` | --help.models output (`--help.models`) | none | 8 | 0.0 s |  |
-| `cli_missing_beta` | error output when BETA is missing (B1: exit code is 0) | `test/regression/inputs/cli_missing_beta` | 8 | 0.0 s | B1; expects exception |
+| `cli_missing_beta` | error output and failing exit status when BETA is missing | `test/regression/inputs/cli_missing_beta` | 8 | 0.4 s | expects exception |
 
 ## Full set (examples as shipped, opt-in)
 
@@ -95,7 +97,7 @@ Generated by `manifest.py` from `reference/`, `cases.py` and `tolerances.json`.
 
 | Case | Covers | Inputs | Datasets | Runtime | Flags |
 |---|---|---|---|---|---|
-| `components` | kernel matrices (11 reachable kernel types), grids (5 types, odd/even), default models (13), singular values | `components/dump_components.cpp` | 47 | 0.0 s |  |
+| `components` | kernel matrices (11 reachable kernel types), grids (5 types, odd/even), default models (13), singular values | `components/dump_components.cpp` | 49 | 0.4 s |  |
 
 ## Tolerances
 
@@ -119,10 +121,10 @@ Rules are matched in order against '<case>:<dataset>'; the first match applies.
 | `\.chi2\.dat$` | 0 | 1e-07 | observed 1.7e-9 |
 | `:files/` | 1e-15 | 2e-06 | spectra, back-continuations, grids, all other outputs; observed 1.5e-7 (GCC 15, u2_time_fast) |
 
-Total compared datasets: 1192 in 60 cases.
+Total compared datasets: 1236 in 62 cases.
 
 ## Known limitations
 
 * The Legendre example is extremely ill-conditioned (minimal chi2 ~ 1e-17): rounding-level differences in the kernel change its alpha probabilities and Ng by up to 3e-3 and 3e-2 between compilers, so its end-to-end tolerances are loose. Kernel changes are caught by the Legendre kernel matrices in `components.h5`, compared at 1e-14. (Checks: Boost Gauss-Kronrod quadrature and, since step 2.2, the closed form used in maxent_kernel.cpp reproduce the GSL Legendre kernels of the references to 2e-16 and 3.3e-16.)
 * `-O0` builds take more than 30 minutes for the full `legendre` case.
-* `*.spex.dat`, `*.fits.dat` and `*.booterr.dat` are not compared (see README.md).
+* `*.spex.dat` and `*.fits.dat` are not compared (see README.md).
diff --git a/test/regression/PROVENANCE.md b/test/regression/PROVENANCE.md
index f7de757..8f3e1b7 100644
--- a/test/regression/PROVENANCE.md
+++ b/test/regression/PROVENANCE.md
@@ -1,9 +1,10 @@
 # Provenance of the references
 
-The references in `reference/` were generated on 2026-09-23 from the
+Most references in `reference/` were generated on 2026-09-23 from the
 **original numerics** of Maxent, before any modernization of the code.
-The same information is stored as `provenance.*` attributes at the root of
-every reference file.
+References added or deliberately regenerated later are identified in the
+dated sections below and in `REFERENCE_CHANGES.md`. Corresponding provenance
+is stored as `provenance.*` attributes at each reference root.
 
 ## Source
 
@@ -54,11 +55,33 @@ Its synthetic Gaussian-spectrum input has zero error bars, so the clock-seeded
 bootstrap is deterministic; three consecutive generate-and-compare runs
 passed.
 
+## Bootstrap-error reference (added 2026-09-24)
+
+`t_generate_err.h5` was generated from `modernize/step2.3c` after commit
+`379b2f0`, using the Release build with AppleClang 21, libc++, C++17, and the
+local ALPSCore installation. It uses the new default `SEED=0`; two independent
+generations were identical. `t_generate_err_seed.h5` was added after commit
+`8b2ff05` with explicit `SEED=1234`; its bootstrap values differ from the
+default-seed reference, so the case detects an ignored `SEED` parameter. Both
+references include `case.out.booterr.dat`.
+
+## Time-bosonic references updated (B7b, 2026-09-24)
+
+The `kernel_time_bosonic` datasets in `components.h5` and the
+`t_kernel_time_bosonic.h5` reference were regenerated from
+`modernize/step2.3c` after commit `46b5610`, using the Release build with
+AppleClang 21 and libc++. All other component datasets are unchanged.
+The component reference also adds a symmetric-grid time-bosonic kernel to
+cover a negative first frequency and the exact ω=0 branch.
+
 ## Determinism
 
-Two independent generations with the reference build were compared with
-`compare.py --report`: all 1165 datasets (1157 numeric, 8 text) in 56 cases
-were bit-identical.
+For the initial 2026-09-23 baseline, two independent generations were compared
+with `compare.py --report`: all 1165 datasets (1157 numeric, 8 text) in the
+original 56 cases were bit-identical. After the subsequently documented
+reference additions and updates, the current inventory is 1236 compared
+datasets (1228 numeric, 8 text) in 62 cases; see `MANIFEST.md` for the generated
+current count.
 
 ## Variant builds (tolerance measurement)
 
diff --git a/test/regression/README.md b/test/regression/README.md
index eb1dc3e..dbc9bbe 100644
--- a/test/regression/README.md
+++ b/test/regression/README.md
@@ -73,8 +73,10 @@ Each result file holds:
   copied dataset by dataset at full precision. Text tables (`*.dat`) are loaded
   as float64, but only carry the 10 significant digits Maxent writes.
   `*.spex.dat` and `*.fits.dat` (spectrum and fit at every α; large, and
-  covered by `chi2.dat`, the α probabilities and the `*_back.dat` files) and
-  `*.booterr.dat` (random, B10) are not packed.
+  covered by `chi2.dat`, the α probabilities and the `*_back.dat` files) are
+  not packed. Bootstrap error output is deterministic (`SEED=0` by default)
+  and is covered by `t_generate_err`; `t_generate_err_seed` verifies an
+  explicit non-default seed.
 * `/log/scalars/`: values parsed from the logs: minimal χ², posterior
   probability of the default model, Ng, number of singular values kept, and
   the number of α values where the minimizer hit `MAX_IT`.
diff --git a/test/regression/REFERENCE_CHANGES.md b/test/regression/REFERENCE_CHANGES.md
index 503ff6d..ebb3feb 100644
--- a/test/regression/REFERENCE_CHANGES.md
+++ b/test/regression/REFERENCE_CHANGES.md
@@ -4,6 +4,64 @@ Every regeneration of files in `reference/` is logged here: date, commit,
 reason, affected cases, and the largest difference to the previous
 references (from `compare.py --report`). Newest entry first.
 
+## 2026-09-24: explicit bootstrap seed coverage
+
+* **Source:** `modernize/step2.3c` after commit `8b2ff05`.
+* **Reason:** added review-requested coverage proving that a non-default
+  `SEED` value is parsed and used, rather than only testing the default.
+* **Cases:** added `t_generate_err_seed` with `SEED=1234`, including
+  `booterr.dat`. It uses the exact input of the default-seed case, isolating
+  the seed as the only cause of bootstrap differences. No existing reference
+  changed.
+
+## 2026-09-24: log-grid float casts removed (B15)
+
+* **Source:** `modernize/step2.3c` after commit `b1d7c8b`.
+* **Reason:** log-grid intermediates now remain explicitly in double
+  precision instead of passing integer indices through `float`.
+* **Cases:** `t_grid_log` and both log-grid component sizes were measured.
+  They are bit-identical, so no reference was regenerated.
+
+## 2026-09-24: time-bosonic zero-frequency limit corrected (B7b)
+
+* **Source:** `modernize/step2.3c` after commit `46b5610`.
+* **Reason:** the time-bosonic kernel previously assigned the ω→0 limit to
+  column 0 regardless of that column's frequency. It now uses the limit only
+  when ω is exactly zero and evaluates the kernel formula everywhere else.
+* **Cases:** `t_kernel_time_bosonic` and `components`; added a symmetric-grid
+  time-bosonic component that contains both negative and exactly zero ω.
+* **Largest differences:** 2.202e-3 relative in the kernel component; 5.373e-4
+  relative in χ² and 1.190e-2 relative in the small spectrum variance.
+
+## 2026-09-24: reproducible bootstrap errors (B10)
+
+* **Source:** `modernize/step2.3c` after commit `379b2f0`.
+* **Reason:** bootstrap error generation now uses the user-selectable `SEED`
+  parameter, which defaults to 0 instead of the wall clock.
+* **Cases:** added `t_generate_err`, including `booterr.dat`; updated
+  `cli_help` for the new parameter. No existing numerical reference changed.
+* **Verification:** two independent runs with the default seed were identical.
+
+## 2026-09-24: grid spelling and help corrected (B16)
+
+* **Source:** `modernize/step2.3c`, based on merge commit `454f7ee`.
+* **Reason:** expected help-text correction: `--help.grids` now reports the
+  actual `CUT=0.01` default. The documented `half-lorentzian` spelling is now
+  accepted as an alias for `half lorentzian`.
+* **Cases:** `cli_help_grids` text only. The targeted half-Lorentzian case now
+  uses the hyphenated alias and remains within its existing numerical
+  tolerance; no numerical reference was regenerated.
+
+## 2026-09-24: command-line failures return nonzero (B1)
+
+* **Source:** `modernize/step2.3c`, based on merge commit `454f7ee`.
+* **Reason:** expected behavior change: Maxent now returns status 1 on errors
+  and reports standard exceptions with `e.what()` instead of Boost diagnostic
+  formatting.
+* **Cases:** `cli_missing_beta` only. Exit status changed from 0 to 1; stderr
+  changed from the multi-line Boost diagnostic to
+  `Caught Exception: Critical parameters not defined`.
+
 ## 2026-09-24: legendre_convert reference added
 
 * **Source:** `modernize/step2` merge commit `a57f150`; the utility is still
diff --git a/test/regression/cases.py b/test/regression/cases.py
index 43b89b2..8e21c54 100644
--- a/test/regression/cases.py
+++ b/test/regression/cases.py
@@ -44,7 +44,7 @@
     ("t_param_xi",            "data as X_i/SIGMA_i in parameter file, frequency PH", []),
     ("t_param_taui",          "X_i/SIGMA_i/TAU_i in parameter file, time fermionic", []),
     ("t_kernel_tzero",        "T=0 kernel, OMEGA_MIN=0", []),
-    ("t_kernel_time_bosonic", "time bosonic kernel, OMEGA_MIN=0", ["B7 (fixed; K(i,0)=T assumes the grid starts at 0)"]),
+    ("t_kernel_time_bosonic", "time bosonic kernel, OMEGA_MIN=0", []),
     ("t_kernel_anomalous_ph", "anomalous kernel, frequency PH", []),
     ("t_kernel_anomalous_nonph", "anomalous kernel, frequency non-PH", []),
     ("t_kernel_legendre_bosonic", "Legendre bosonic kernel", ["B17 (Legendre bosonic uses the fermionic integrand)"]),
@@ -62,10 +62,12 @@
     ("t_model_quadratic_rise_exp_decay", "default model: quadratic rise exp decay (T=0 kernel, OMEGA_MIN=0)", []),
     ("t_model_tabulated",     "default model: tabulated file", []),
     ("t_grid_lorentzian",     "grid: lorentzian", []),
-    ("t_grid_half_lorentzian", "grid: half lorentzian", ["B16 (help text says 'half-lorentzian')"]),
+    ("t_grid_half_lorentzian", "grid: half-lorentzian alias", []),
     ("t_grid_quadratic",      "grid: quadratic", []),
     ("t_grid_log",            "grid: log", []),
     ("t_grid_linear",         "grid: linear", []),
+    ("t_generate_err",         "bootstrap error bars with the default SEED=0", []),
+    ("t_generate_err_seed",    "bootstrap error bars with explicit SEED=1234", []),
     ("t_model_runs",          "MODEL_RUNS=2 (flat, gaussian): per-model outputs and varspec", []),
 ]
 
@@ -73,7 +75,7 @@
     ("cli_help",         ["--help"],        "--help output"),
     ("cli_help_models",  ["--help.models"], "--help.models output"),
     ("cli_help_grids",   ["--help.grids"],  "--help.grids output"),
-    ("cli_missing_beta", None,              "error output when BETA is missing (B1: exit code is 0)"),
+    ("cli_missing_beta", None,              "error output and failing exit status when BETA is missing"),
 ]
 
 
@@ -115,12 +117,12 @@ def all_cases():
     for name, args, covers in CLI:
         if args is None:
             cases.append(dict(name=name, set="cli", inputs="test/regression/inputs/" + name,
-                              param="case.param", args=[], covers=covers, flags=["B1"],
+                              param="case.param", args=[], covers=covers, flags=[],
                               expect="exception"))
         else:
             cases.append(dict(name=name, set="cli", inputs=None, param=None,
                               args=args, covers=covers,
-                              flags=["B16"] if name == "cli_help_grids" else [],
+                              flags=[],
                               expect="ok"))
     for name, direction, covers in KK:
         cases.append(dict(name=name, set="kk", program="kk", inputs="test/regression/inputs/" + name,
diff --git a/test/regression/components/dump_components.cpp b/test/regression/components/dump_components.cpp
index b1fb3ef..55d243b 100644
--- a/test/regression/components/dump_components.cpp
+++ b/test/regression/components/dump_components.cpp
@@ -58,9 +58,9 @@ alps::params base_params() {
 
 // ---------------------------------------------------------------- kernels
 void dump_kernel(const std::string &name, const std::string &dataspace, const std::string &kernel_name,
-                 bool ph, int ndat, double omega_min, double omega_max, bool time_input) {
+                 bool ph, int ndat, double omega_min, double omega_max, bool time_input,
+                 int nfreq = 24) {
   alps::params p = base_params();
-  const int nfreq = 24;
   p["NDAT"] = ndat;
   p["NFREQ"] = nfreq;
   p["DATASPACE"] = dataspace;
@@ -137,6 +137,7 @@ int main(int argc, char **argv) {
   // kernels: every kernel type reachable through set_kernel_type (the time-Legendre types are not, B5)
   dump_kernel("time_fermionic", "time", "fermionic", false, 9, -6, 6, true);
   dump_kernel("time_bosonic", "time", "bosonic", false, 9, 0, 6, true);
+  dump_kernel("time_bosonic_symmetric", "time", "bosonic", false, 9, -6, 6, true, 25);
   dump_kernel("time_tzero", "time", "tzero", false, 9, 0, 6, true);
   dump_kernel("legendre_fermionic", "legendre", "fermionic", true, 6, -6, 6, false);
   dump_kernel("legendre_bosonic", "legendre", "bosonic", true, 6, -6, 6, false);
diff --git a/test/regression/generate.py b/test/regression/generate.py
index 8d5007c..f59208c 100644
--- a/test/regression/generate.py
+++ b/test/regression/generate.py
@@ -18,7 +18,7 @@
 
 Not packed: *.spex.dat and *.fits.dat (spectrum and fit for every alpha: they
 grow like N_ALPHA x NFREQ or N_ALPHA x NDAT, and are covered by chi2.dat, the
-alpha probabilities and the *_back.dat files) and *.booterr.dat (random, B10).
+alpha probabilities and the *_back.dat files).
 """
 
 import argparse
@@ -40,7 +40,7 @@
 sys.path.insert(0, str(HERE))
 from cases import all_cases  # noqa: E402
 
-SKIP_OUTPUTS = re.compile(r"\.(spex|fits|booterr)\.dat$")
+SKIP_OUTPUTS = re.compile(r"\.(spex|fits)\.dat$")
 SCALARS = {
     "minimal_chi2": re.compile(r"^minimal chi2: (\S+)", re.M),
     "posterior_probability": re.compile(r"^posterior probability of the default model: (\S+)", re.M),
@@ -62,6 +62,17 @@ def run(cmd, cwd, timeout=TIMEOUT):
     return p, time.monotonic() - t0
 
 
+def classify_status(program, returncode, stderr):
+    """Classify command completion without mistaking crashes for exceptions."""
+    if returncode is None:
+        return "timeout"
+    if program == "maxent" and returncode == 1 and "Caught Exception:" in stderr:
+        return "exception"
+    if returncode != 0:
+        return "failed"
+    return "ok"
+
+
 def pack_outputs(h5, workdir, before):
     files = h5.create_group("files")
     for path in sorted(workdir.rglob("*")):
@@ -114,11 +125,10 @@ def run_case(case, programs, outdir, provenance, timeout=TIMEOUT):
         before = {p.relative_to(workdir).as_posix() for p in workdir.rglob("*")}
         cmd = [str(programs[case["program"]])] + ([case["param"]] if case["param"] else []) + case["args"]
         p, seconds = run(cmd, workdir, timeout)
-        # maxent always exits with 0 (B1) and reports errors as 'Caught Exception';
-        # the other programs report failure through their exit code
-        status = "timeout" if p.returncode is None else \
-            "exception" if "Caught Exception" in p.stderr else \
-            "failed" if case["program"] != "maxent" and p.returncode != 0 else "ok"
+        # An expected Maxent exception has both the documented exit status and
+        # diagnostic signature. Crashes and other nonzero exits remain generic
+        # failures rather than accidentally satisfying an exception case.
+        status = classify_status(case["program"], p.returncode, p.stderr)
         with h5py.File(out, "w") as h5:
             for key in ("name", "set", "covers"):
                 h5.attrs[key] = case[key]
diff --git a/test/regression/inputs/t_generate_err/case.param b/test/regression/inputs/t_generate_err/case.param
new file mode 100644
index 0000000..e8c3cf9
--- /dev/null
+++ b/test/regression/inputs/t_generate_err/case.param
@@ -0,0 +1,9 @@
+BETA=5.0
+NFREQ=40
+N_ALPHA=8
+NDAT=24
+DATASPACE=frequency
+KERNEL=fermionic
+PARTICLE_HOLE_SYMMETRY=true
+DATA="data.dat"
+GENERATE_ERR=true
diff --git a/test/regression/inputs/t_generate_err/data.dat b/test/regression/inputs/t_generate_err/data.dat
new file mode 100644
index 0000000..d74bcda
--- /dev/null
+++ b/test/regression/inputs/t_generate_err/data.dat
@@ -0,0 +1,24 @@
+0.62831853071795862 -0.80874290991409159 0.0001
+1.8849555921538759 -0.44014716084961508 0.0001
+3.1415926535897931 -0.29286728018013575 0.0001
+4.3982297150257104 -0.21712083835923829 0.0001
+5.6548667764616276 -0.17165635623034461 0.0001
+6.911503837897544 -0.14166307358889488 0.0001
+8.1681408993334621 -0.12060505637657916 0.0001
+9.4247779607693793 -0.10485266703834568 0.0001
+10.681415022205297 -0.092950172398290121 0.0001
+11.938052083641214 -0.083168742498363424 0.0001
+13.194689145077131 -0.075316139276522379 0.0001
+14.451326206513048 -0.068980526475614631 0.0001
+15.707963267948966 -0.063426614004070431 0.0001
+16.964600329384883 -0.058669718153089162 0.0001
+18.2212373908208 -0.054868212835967246 0.0001
+19.477874452256717 -0.051194487824511997 0.0001
+20.734511513692635 -0.048183803227436109 0.0001
+21.991148575128552 -0.045353889185727227 0.0001
+23.247785636564469 -0.04311132391388374 0.0001
+24.504422698000386 -0.040812383784974739 0.0001
+25.7610597594363 -0.038789286218401768 0.0001
+27.017696820872221 -0.037114935461959209 0.0001
+28.274333882308138 -0.035393491249622627 0.0001
+29.530970943744059 -0.033879643568396858 0.0001
diff --git a/test/regression/inputs/t_generate_err_seed/case.param b/test/regression/inputs/t_generate_err_seed/case.param
new file mode 100644
index 0000000..ad67256
--- /dev/null
+++ b/test/regression/inputs/t_generate_err_seed/case.param
@@ -0,0 +1,10 @@
+BETA=5.0
+NFREQ=40
+N_ALPHA=8
+NDAT=24
+DATASPACE=frequency
+KERNEL=fermionic
+PARTICLE_HOLE_SYMMETRY=true
+DATA="data.dat"
+GENERATE_ERR=true
+SEED=1234
diff --git a/test/regression/inputs/t_generate_err_seed/data.dat b/test/regression/inputs/t_generate_err_seed/data.dat
new file mode 100644
index 0000000..d74bcda
--- /dev/null
+++ b/test/regression/inputs/t_generate_err_seed/data.dat
@@ -0,0 +1,24 @@
+0.62831853071795862 -0.80874290991409159 0.0001
+1.8849555921538759 -0.44014716084961508 0.0001
+3.1415926535897931 -0.29286728018013575 0.0001
+4.3982297150257104 -0.21712083835923829 0.0001
+5.6548667764616276 -0.17165635623034461 0.0001
+6.911503837897544 -0.14166307358889488 0.0001
+8.1681408993334621 -0.12060505637657916 0.0001
+9.4247779607693793 -0.10485266703834568 0.0001
+10.681415022205297 -0.092950172398290121 0.0001
+11.938052083641214 -0.083168742498363424 0.0001
+13.194689145077131 -0.075316139276522379 0.0001
+14.451326206513048 -0.068980526475614631 0.0001
+15.707963267948966 -0.063426614004070431 0.0001
+16.964600329384883 -0.058669718153089162 0.0001
+18.2212373908208 -0.054868212835967246 0.0001
+19.477874452256717 -0.051194487824511997 0.0001
+20.734511513692635 -0.048183803227436109 0.0001
+21.991148575128552 -0.045353889185727227 0.0001
+23.247785636564469 -0.04311132391388374 0.0001
+24.504422698000386 -0.040812383784974739 0.0001
+25.7610597594363 -0.038789286218401768 0.0001
+27.017696820872221 -0.037114935461959209 0.0001
+28.274333882308138 -0.035393491249622627 0.0001
+29.530970943744059 -0.033879643568396858 0.0001
diff --git a/test/regression/inputs/t_grid_half_lorentzian/case.param b/test/regression/inputs/t_grid_half_lorentzian/case.param
index 110c996..2da8dbc 100644
--- a/test/regression/inputs/t_grid_half_lorentzian/case.param
+++ b/test/regression/inputs/t_grid_half_lorentzian/case.param
@@ -6,4 +6,4 @@ DATASPACE=frequency
 KERNEL=fermionic
 PARTICLE_HOLE_SYMMETRY=true
 DATA="data.dat"
-FREQUENCY_GRID="half lorentzian"
+FREQUENCY_GRID=half-lorentzian
diff --git a/test/regression/make_inputs.py b/test/regression/make_inputs.py
index cb8033a..eba4efa 100644
--- a/test/regression/make_inputs.py
+++ b/test/regression/make_inputs.py
@@ -306,9 +306,20 @@ def make(name, case_dir):
         else:
             base_frequency_ph(case_dir, name, options)
     elif name.startswith("t_grid_"):
-        grid = {"lorentzian": "lorentzian", "half_lorentzian": '"half lorentzian"',
+        grid = {"lorentzian": "lorentzian", "half_lorentzian": "half-lorentzian",
                 "quadratic": "quadratic", "log": "log", "linear": "linear"}[name[len("t_grid_"):]]
         base_frequency_ph(case_dir, name, [("FREQUENCY_GRID", grid)])
+    elif name in ("t_generate_err", "t_generate_err_seed"):
+        # Keep the scientific input identical so the two cases isolate SEED.
+        wn, y = freq_ph_data("t_generate_err")
+        write_columns(case_dir / "data.dat", wn, y, np.full_like(y, NOISE))
+        entries = [("BETA", BETA), ("NFREQ", 40), ("N_ALPHA", 8),
+                   ("NDAT", wn.size), ("DATASPACE", "frequency"),
+                   ("KERNEL", "fermionic"), ("PARTICLE_HOLE_SYMMETRY", "true"),
+                   ("DATA", '"data.dat"'), ("GENERATE_ERR", "true")]
+        if name == "t_generate_err_seed":
+            entries.append(("SEED", 1234))
+        write_param(case_dir, entries)
     elif name in ("kk_imag_to_real_green", "kk_imag_to_real_self"):
         source, dataset, scale = {
             "kk_imag_to_real_green": ("u0_frequency", "files/in.out.avspec.dat", -np.pi),
diff --git a/test/regression/manifest.py b/test/regression/manifest.py
index d5ba99d..88bd198 100644
--- a/test/regression/manifest.py
+++ b/test/regression/manifest.py
@@ -87,7 +87,7 @@ def main():
               "quadrature and, since step 2.2, the closed form used in maxent_kernel.cpp reproduce the GSL "
               "Legendre kernels of the references to 2e-16 and 3.3e-16.)",
               "* `-O0` builds take more than 30 minutes for the full `legendre` case.",
-              "* `*.spex.dat`, `*.fits.dat` and `*.booterr.dat` are not compared (see README.md).", ""]
+              "* `*.spex.dat` and `*.fits.dat` are not compared (see README.md).", ""]
     (HERE / "MANIFEST.md").write_text("\n".join(lines))
     print(f"wrote MANIFEST.md: {len(cases)} cases, {total} datasets")
 
diff --git a/test/regression/reference/cli_help.h5 b/test/regression/reference/cli_help.h5
index 9b86415..da90fd5 100644
Binary files a/test/regression/reference/cli_help.h5 and b/test/regression/reference/cli_help.h5 differ
diff --git a/test/regression/reference/cli_help_grids.h5 b/test/regression/reference/cli_help_grids.h5
index a820e21..ebf022f 100644
Binary files a/test/regression/reference/cli_help_grids.h5 and b/test/regression/reference/cli_help_grids.h5 differ
diff --git a/test/regression/reference/cli_missing_beta.h5 b/test/regression/reference/cli_missing_beta.h5
index 0c603d9..9051b9c 100644
Binary files a/test/regression/reference/cli_missing_beta.h5 and b/test/regression/reference/cli_missing_beta.h5 differ
diff --git a/test/regression/reference/components.h5 b/test/regression/reference/components.h5
index 7717fff..088f09a 100644
Binary files a/test/regression/reference/components.h5 and b/test/regression/reference/components.h5 differ
diff --git a/test/regression/reference/t_generate_err.h5 b/test/regression/reference/t_generate_err.h5
new file mode 100644
index 0000000..3f5710a
Binary files /dev/null and b/test/regression/reference/t_generate_err.h5 differ
diff --git a/test/regression/reference/t_generate_err_seed.h5 b/test/regression/reference/t_generate_err_seed.h5
new file mode 100644
index 0000000..7dca1ee
Binary files /dev/null and b/test/regression/reference/t_generate_err_seed.h5 differ
diff --git a/test/regression/reference/t_kernel_time_bosonic.h5 b/test/regression/reference/t_kernel_time_bosonic.h5
index b4d4029..316c6ea 100644
Binary files a/test/regression/reference/t_kernel_time_bosonic.h5 and b/test/regression/reference/t_kernel_time_bosonic.h5 differ
diff --git a/test/regression/test_generate.py b/test/regression/test_generate.py
new file mode 100644
index 0000000..25f62d7
--- /dev/null
+++ b/test/regression/test_generate.py
@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: MIT
+
+import unittest
+
+from generate import classify_status
+
+
+class ClassifyStatusTest(unittest.TestCase):
+    def test_timeout(self):
+        self.assertEqual(classify_status("maxent", None, ""), "timeout")
+
+    def test_expected_maxent_exception(self):
+        self.assertEqual(classify_status("maxent", 1, "Caught Exception: bad input\n"),
+                         "exception")
+
+    def test_maxent_exit_without_signature_is_failure(self):
+        self.assertEqual(classify_status("maxent", 1, ""), "failed")
+
+    def test_maxent_wrong_exit_with_signature_is_failure(self):
+        self.assertEqual(classify_status("maxent", 2, "Caught Exception: bad input\n"),
+                         "failed")
+
+    def test_success_ignores_diagnostic_text(self):
+        self.assertEqual(classify_status("maxent", 0, "Caught Exception: stale log\n"), "ok")
+
+    def test_utility_nonzero_exit_is_failure(self):
+        self.assertEqual(classify_status("kk", 1, "Caught Exception: bad input\n"), "failed")
+
+
+if __name__ == "__main__":
+    unittest.main()