Specify tight frozen-direction trials after gravity-path stall

experiments/COUPLED_CONVERGENCE_STUDY_2026-09-19.md

@@ -137,6 +137,13 @@ derivative, so a large nonlinear closure residual must not be described as
 proof of a missing EOS cross derivative. Frozen block defects and finite-step
 closure remainders distinguish those possibilities.
 
+The live gravity-path comparison initially accepts an eight-times-larger step
+but returns to smaller steps by its third update. Before the frozen campaign,
+extend raw trial observations to the eta=1e-7 n=2 benchmark as well: if that
+linear accuracy is attained, its trial data can test whether a more accurate
+direction relieves curvature. A failed linear gate will remain labeled as
+such, regardless of whether a sampled nonlinear trial happens to decrease.
+
 The small Schur block contains all 25 surface parameters and every generated
 scalar. Its field inverse is the unbordered structure inverse; restricting an
 already scalar-bordered inverse could spuriously constrain the field solve.

experiments/convergence_linear_cases_2026-09-19.json

@@ -126,7 +126,8 @@
       "--restart-snapshot",
       "../../diagnostics/coupled_convergence_2026-09-19/screen_v1/n2_J0/capture_3/physical_base.txt",
       "--allow-unconverged-restart",
-      "--no-central"
+      "--no-central",
+      "--benchmark-trials"
     ]
   },
   {