diff --git a/PARITY.md b/PARITY.md
index d88cfc88..6dc0baeb 100644
--- a/PARITY.md
+++ b/PARITY.md
@@ -1167,6 +1167,19 @@ events over the full duration. These measurements do not establish a
 step-converged 600 s physical reference or change the case badge. The
 separate matched MATLAB 0.005-to-0.0025 s audit addresses the 160 s prefix.
 
+A further independent physical `WEC.run` refinement to `0.000625` s through
+250 s uses the same pinned sea and heading bank. Relative to the `0.00125` s
+Python path, it passes the unchanged yaw, yaw-speed, torque, and work limits
+through 120 s but fails yaw and work by 140 s; the first yaw-limit breach is
+at 139.7725 s. At 250 s the yaw gap is `0.01966` rad and the relative PTO-work
+gap is `0.965%`, compared with `0.01256` rad and `0.0552%` for the preceding
+`0.0025`-to-`0.00125` s refinement. Thus this third step does not support a
+monotonic convergence claim for the physical selected-heading path. Its
+direct comparison with published 0.01 s MATLAB also fails the unchanged
+limits by 140 s; at 250 s yaw differs by `0.02082` rad and PTO work by
+`1.286%`. The window metrics, input hashes, and evaluator hashes are in the
+linked audit; the full published 600 s case remains qualified.
+
 ![OSWEC variable-yaw published, source-step, and Python-step yaw differences](docs/figures/oswec-variable-yaw-step-gap.png)
 
 The already gated 300 s OSWEC `Desalination` network and coupled-motion
diff --git a/docs/evidence/oswec-variable-yaw-refinement.json b/docs/evidence/oswec-variable-yaw-refinement.json
index 7887f575..82ef6b6a 100644
--- a/docs/evidence/oswec-variable-yaw-refinement.json
+++ b/docs/evidence/oswec-variable-yaw-refinement.json
@@ -1,6 +1,7 @@
 {
   "first_yaw_limit_breach_s": {
     "matlab_0p005_vs_published_0p01": 142.93,
+    "python_0p000625_vs_0p00125": 139.7725,
     "python_0p00125_vs_0p0025": 167.73,
     "python_0p0025_vs_published_0p01": 166.98
   },
@@ -20,7 +21,7 @@
     "significant_wave_height_m": 2.5,
     "wave_direction_deg": 10
   },
-  "interpretation": "Both MATLAB source and physical Python paths are step-sensitive after heading-event separation. A separate matched MATLAB 0.005-to-0.0025 s audit examines the 160 s prefix. These results do not establish full 600 s physical parity or increase badge counts.",
+  "interpretation": "Both MATLAB source and physical Python paths are step-sensitive after heading-event separation. A third Python refinement from 0.00125 to 0.000625 s fails the same yaw and work limits by 140 s and has a larger 250 s yaw change than the preceding refinement, so physical step convergence is unproven. A separate matched MATLAB 0.005-to-0.0025 s audit examines the 160 s prefix. These results do not establish full 600 s physical parity or increase badge counts.",
   "matlab_local_half_replay": {
     "heading_mismatch_samples": 0,
     "max_pto_torque_Nm": 1.2005330063402653e-10,
@@ -64,6 +65,90 @@
     "yaw_rad": 0.0006,
     "yaw_speed_rad_s": 0.00015
   },
+  "python_0p000625_vs_0p00125": {
+    "120": {
+      "coarse_work_J": 1152.9816251275417,
+      "fine_work_J": 1152.503161350514,
+      "gate_pass": true,
+      "heading_mismatch_samples": 549,
+      "pto_torque_Nm": 3.379088083837246,
+      "pto_work_relative": 0.0004151518130910693,
+      "yaw_rad": 0.00018914658027673753,
+      "yaw_speed_rad_s": 2.81590673653102e-05
+    },
+    "140": {
+      "coarse_work_J": 1467.504883949558,
+      "fine_work_J": 1465.353858607261,
+      "gate_pass": false,
+      "heading_mismatch_samples": 1497,
+      "pto_torque_Nm": 12.626656486160158,
+      "pto_work_relative": 0.0014679221197407713,
+      "yaw_rad": 0.0006210590209511924,
+      "yaw_speed_rad_s": 0.00010522213738466818
+    },
+    "160": {
+      "coarse_work_J": 1622.0080590687708,
+      "fine_work_J": 1624.965746361694,
+      "gate_pass": false,
+      "heading_mismatch_samples": 6875,
+      "pto_torque_Nm": 65.12605621399831,
+      "pto_work_relative": 0.001820153624496754,
+      "yaw_rad": 0.002953410750665464,
+      "yaw_speed_rad_s": 0.0005427171351166525
+    },
+    "250": {
+      "coarse_work_J": 1913.0788661318934,
+      "fine_work_J": 1931.7245416759756,
+      "gate_pass": false,
+      "heading_mismatch_samples": 53334,
+      "pto_torque_Nm": 402.48998512317814,
+      "pto_work_relative": 0.009652346978987555,
+      "yaw_rad": 0.019659801420446266,
+      "yaw_speed_rad_s": 0.0033540832093598176
+    }
+  },
+  "python_0p000625_vs_published": {
+    "120": {
+      "heading_mismatch_samples": 86,
+      "motion_work_limits_pass": true,
+      "pto_torque_Nm": 3.9015471294851523,
+      "pto_work_relative": 0.00033885197543386306,
+      "python_work_J": 1152.503161350514,
+      "source_work_J": 1152.8938216994623,
+      "yaw_rad": 0.00019700751603793365,
+      "yaw_speed_rad_s": 3.2512892745596364e-05
+    },
+    "140": {
+      "heading_mismatch_samples": 225,
+      "motion_work_limits_pass": false,
+      "pto_torque_Nm": 14.980815388654378,
+      "pto_work_relative": 0.0013719295995725722,
+      "python_work_J": 1465.353858607261,
+      "source_work_J": 1467.3669828044058,
+      "yaw_rad": 0.0007164278005663272,
+      "yaw_speed_rad_s": 0.00012484012823884639
+    },
+    "160": {
+      "heading_mismatch_samples": 938,
+      "motion_work_limits_pass": false,
+      "pto_torque_Nm": 69.5069605340257,
+      "pto_work_relative": 0.0021963996294416905,
+      "python_work_J": 1624.965746361694,
+      "source_work_J": 1621.4044941316083,
+      "yaw_rad": 0.0032135961672776214,
+      "yaw_speed_rad_s": 0.0005792246711169074
+    },
+    "250": {
+      "heading_mismatch_samples": 7061,
+      "motion_work_limits_pass": false,
+      "pto_torque_Nm": 423.6648447154714,
+      "pto_work_relative": 0.012863660766330831,
+      "python_work_J": 1931.7245416759756,
+      "source_work_J": 1907.191082573183,
+      "yaw_rad": 0.020824665104405143,
+      "yaw_speed_rad_s": 0.0035305403726289537
+    }
+  },
   "python_0p00125_vs_0p0025": {
     "120": {
       "coarse_work_J": 1152.872348903958,
@@ -174,6 +259,10 @@
     "version": "3.12.7"
   },
   "python_runs": {
+    "dt_0p000625_duration_s": 250,
+    "dt_0p000625_evaluator_sha256": "b438b1f9a0b9bda686315e8361c8a6b78ff652dbfc29288bd973485c59d8842b",
+    "dt_0p000625_output_sha256": "5a526e6810e48983be8c502b64cebc14b679956c1bf0a5876475e5a9ced7cdc3",
+    "dt_0p000625_script_sha256": "efa721a233b4cc7a4fce89471422c1175f6a02637f3295ead8aa1597d6d4c9a8",
     "dt_0p00125_output_sha256": "f3d6ed2e8980ec5bd8ec900747d31444d4308656701edf01223060d1cf6b7416",
     "dt_0p00125_script_sha256": "81d34286649c290c086b5cb541eccc6a8b66c0a2eb30172e21327df8429d5154",
     "dt_0p0025_output_sha256": "bca46ccdb9341b456a114e0218108c9fbb53142a100610ea2e207434edf5184a",
diff --git a/docs/figures/oswec-variable-yaw-step-gap.png b/docs/figures/oswec-variable-yaw-step-gap.png
index bb434ecb..f31c2022 100644
Binary files a/docs/figures/oswec-variable-yaw-step-gap.png and b/docs/figures/oswec-variable-yaw-step-gap.png differ
diff --git a/tests/reference_case_status.csv b/tests/reference_case_status.csv
index 8084076e..bca26f0b 100644
--- a/tests/reference_case_status.csv
+++ b/tests/reference_case_status.csv
@@ -55,7 +55,7 @@ Passive_Yaw/PassiveYawRegression,qualified_motion,Opt-in source ode4 independent
 RM3_PTO_Extension/float,qualified_motion,Published-step opt-in source ode4 pairs; physical Python pairs a derived full-duration FixedStep-only source and exposes published ode4 step sensitivity.
 RM3_PTO_Extension/spar,qualified_motion,Published-step opt-in source ode4 pairs; physical Python pairs a derived full-duration FixedStep-only source and exposes published ode4 step sensitivity.
 Radiation_Force_Options,independent_motion,"All four radiation modes have motion gates; the fitted state-space option is nonpassive."
-Variable_Hydro/Passive_Yaw,mixed_modes,Published regular-wave motion and opt-in source ode4 numerical irregular motion are gated; both the MATLAB source and physical Python irregular paths are step-sensitive after heading events through 600 s; no full physical irregular gate is claimed.
+Variable_Hydro/Passive_Yaw,mixed_modes,Published regular-wave motion and opt-in source ode4 numerical irregular motion are gated; MATLAB irregular motion is source-step sensitive and the physical Python path fails a third-step self-convergence check by 140 s; no full physical irregular gate is claimed.
 Variable_Hydro/Variable_Mass,independent_motion,Full 900 s body motion and PTO stroke force speed absorbed power and integrated work independently pair across all nine draft states.
 WECCCOMP/WECCCOMP,independent_motion,
 WECCCOMP/WECCCOMP_Fault_Implementation,independent_motion,