diff --git a/docs/decisions/ADR-0024-inner-loop-admissibility.md b/docs/decisions/ADR-0024-inner-loop-admissibility.md
index b1a445bc..ae46bd58 100644
--- a/docs/decisions/ADR-0024-inner-loop-admissibility.md
+++ b/docs/decisions/ADR-0024-inner-loop-admissibility.md
@@ -182,3 +182,111 @@ user-controlled text enters the trace path.
 Set `inner_loop_admissibility=False` (the default) at every call
 site.  The trace hash remains byte-identical to ADR-0023, so
 deterministic replay over the existing corpus is unaffected.
+
+---
+
+## Addendum — Phase 1 v1/dev fixture retirement (2026-05-17)
+
+### Finding
+
+Phase 4's characterization recorded that v1 chain-token outer-product
+blades skipped 9/9 cases because `chain_tokens` (`alpha`, `beta`,
+`gamma`, `delta`, `mu`, `nu`, `omicron`, `pi`, `rho`, `sigma`, `tau`,
+`upsilon`, `phi`, `chi`, `psi`, `omega`, `iota`, `lambda`, `eta`,
+`theta`, `zeta`, `xenon`, `ytterbium`, `kappa`) were synthetic and
+ungrounded in `en_core_cognition_v1`.  The Phase 2 corpus-observation
+runner inherited the same fixtures, surfacing `exhaustion_rate = 0.33`
+at `t = 0` on v1+dev — above the 5 % benign-corpus ceiling.
+
+Original assessment (pre-Phase-1): "v1 chain construction can produce
+ungrounded regions; fix the cause, not the symptom."
+
+### What Phase 1 did
+
+The 1 v1 case and 8 dev cases were rewritten with pack-grounded tokens
+drawn from `en_core_cognition_v1`:
+
+* `tone → evidence → memory → wisdom` (causes chain, replacing
+  `alpha → beta → gamma → delta`)
+* `voice → memory → wisdom` (means chain, replacing
+  `mu → nu → omicron`)
+* `question → answer → understanding → wisdom` (precedes chain,
+  replacing `pi → rho → sigma → tau`)
+* `word → discourse → narrative` (part_of chain, replacing
+  `upsilon → phi → chi`)
+* `symbol → word → meaning` with `image`/`light` distractors
+  (adversarial branching, replacing `eta/theta/zeta` plus
+  `beta/rho` means-distractors)
+
+All token-level grammar adjustments (e.g. *"register cause memory"* →
+*"register causes memory"*) were corrected as part of the rewrite.
+
+### What changed about the finding
+
+| Metric                                  | Pre-rewrite | Post-rewrite |
+| --------------------------------------- | ----------- | ------------ |
+| v1+dev cases skipped (region builds)    | 9 / 9       | 0 / 9        |
+| `causal_attribution_valid`              | True        | True         |
+| `code_path_residual`                    | 0.0         | 0.0          |
+| `inner_loop_t0` hash stability          | 1.0         | 1.0          |
+| `best_separation_quality` (Phase 4)     | 0.0         | 0.056        |
+| `geometry_supports_static_threshold`    | False       | False        |
+| `inner_loop_t0` exhaustion (Phase 2)    | 0.33        | 0.67         |
+| `inner_loop_tpos` exhaustion (Phase 2)  | (skipped)   | 1.00         |
+
+The original Phase 4 finding ("v1 chain-token blades unsuitable as the
+default region construction") was caused by two layered issues:
+
+1. **Surface fixture rot** — synthetic tokens prevented region
+   construction at all.  This is now fixed.
+2. **Deeper architectural mismatch** — v1's case schema
+   (`prime` + `chain_tokens`) probes *teaching-driven walk* through a
+   relation injected at runtime (ADR-0022 / ADR-0023's mechanism).
+   The inner-loop admissibility lane (ADR-0024) tests
+   *blade-geometric region constraint*.  These are distinct
+   mechanisms; the same case schema cannot meaningfully exercise both.
+
+Exhaustion *increased* post-rewrite because the chain-blade region is
+now constructible *and* actively rejecting the boundary's off-chain
+picks.  That is honest behavior of the inner-loop on cases it was not
+designed to evaluate.
+
+### Architectural conclusion
+
+* **v1 / dev cases belong to the ADR-0022 / ADR-0023 boundary-walk
+  lane (`evals/forward_semantic_control/runner.py`).**  The rewrite
+  improves that lane (real semantic substrate for teaching priming) and
+  does not affect this ADR.
+* **v2 cases belong to the ADR-0024 inner-loop admissibility lane
+  (`evals/forward_semantic_control/v2_runner.py`).**  v2's schema
+  (`seed_token` + `admissible_tokens` + `relation_blade_token`) is the
+  correct fixture shape for blade-admissibility evaluation.
+* **The Phase 2 corpus-observation runner's reuse of v1+dev cases was
+  a categorical error.**  The runner remains useful as a corpus-style
+  observation harness; it now needs a proper benign inner-loop corpus,
+  authored with v2's schema.  Authoring that corpus is **Phase 5's
+  job** (stratified mechanism-isolation families subsume benign-corpus
+  observation).
+
+### What this ADR addendum does *not* claim
+
+* The exhaustion finding is not "closed" — it is reattributed.  v1/dev
+  inner-loop exhaustion at 67 % is an honest consequence of running the
+  wrong mechanism on the wrong fixture, not a defect in the inner-loop
+  implementation.
+* The Phase 2 runner's exhaustion gate (`EXHAUSTION_CEILING = 0.05`)
+  remains valid as a contract; it cannot be satisfied on the current
+  fixture mix.  Phase 5 will produce the benign-corpus fixtures the
+  gate was designed against.
+* Phase 4's "no static threshold passes" finding stands unchanged.
+
+### Tests pinning the new state
+
+* `tests/test_inner_loop_phase4.py::TestV1ChainBladePostGrounding` —
+  asserts `skipped_count == 0` (replacing the pre-rewrite assertion
+  `skipped_count == case_count`) and
+  `best_separation_quality < 0.5` (replacing `== 0.0`).
+* `tests/test_inner_loop_phase2.py` (unchanged) — continues to assert
+  `causal_attribution_valid` and inner-loop hash stability.  No
+  exhaustion gate assertion; exhaustion remains a recorded finding,
+  not an invariant.
diff --git a/evals/forward_semantic_control/dev/cases.jsonl b/evals/forward_semantic_control/dev/cases.jsonl
index 5c942c7f..5e238052 100644
--- a/evals/forward_semantic_control/dev/cases.jsonl
+++ b/evals/forward_semantic_control/dev/cases.jsonl
@@ -1,8 +1,8 @@
-{"id":"FSC-DEV-001","kind":"chain_three_hop","prime":["What does alpha cause?","Actually alpha causes beta.","What does beta cause?","Actually beta causes gamma.","What does gamma cause?","Actually gamma causes delta."],"prompt":"What does alpha cause?","expected_endpoint":"delta","chain_tokens":["alpha","beta","gamma","delta"],"baseline_must_fail":true}
-{"id":"FSC-DEV-002","kind":"negative_control_no_chain","prime":["What does alpha cause?","Actually alpha causes beta.","What does xenon cause?","Actually xenon causes ytterbium."],"prompt":"What does alpha cause?","expected_endpoint":"beta","chain_tokens":["alpha","beta"],"baseline_must_fail":false}
-{"id":"FSC-DEV-003","kind":"frame_constraint_blocks_wrong_relation","prime":["What does alpha cause?","Actually alpha causes beta.","What does alpha mean?","Actually alpha means kappa."],"prompt":"What does alpha cause?","expected_endpoint":"beta","forbidden_token":"kappa","chain_tokens":["alpha","beta"],"baseline_must_fail":false}
-{"id":"FSC-DEV-004","kind":"chain_two_hop_means","prime":["What does mu mean?","Actually mu means nu.","What does nu mean?","Actually nu means omicron."],"prompt":"What does mu mean?","expected_endpoint":"omicron","chain_tokens":["mu","nu","omicron"],"baseline_must_fail":true}
-{"id":"FSC-DEV-005","kind":"chain_three_hop_precedes","prime":["What does pi precede?","Actually pi precedes rho.","What does rho precede?","Actually rho precedes sigma.","What does sigma precede?","Actually sigma precedes tau."],"prompt":"What does pi precede?","expected_endpoint":"tau","chain_tokens":["pi","rho","sigma","tau"],"baseline_must_fail":true}
-{"id":"FSC-DEV-006","kind":"chain_two_hop_part_of","prime":["What is upsilon part of?","Actually upsilon is part of phi.","What is phi part of?","Actually phi is part of chi."],"prompt":"What is upsilon part of?","expected_endpoint":"chi","chain_tokens":["upsilon","phi","chi"],"baseline_must_fail":true}
-{"id":"FSC-DEV-007","kind":"adversarial_distractor_means_vs_cause","prime":["What does psi cause?","Actually psi causes omega.","What does psi mean?","Actually psi means iota.","What does psi precede?","Actually psi precedes lambda."],"prompt":"What does psi cause?","expected_endpoint":"omega","forbidden_token":"iota","chain_tokens":["psi","omega"],"baseline_must_fail":false}
-{"id":"FSC-DEV-008","kind":"adversarial_distractor_chain_branching","prime":["What does eta cause?","Actually eta causes theta.","What does theta cause?","Actually theta causes zeta.","What does eta mean?","Actually eta means beta.","What does theta mean?","Actually theta means rho."],"prompt":"What does eta cause?","expected_endpoint":"zeta","forbidden_token":"rho","chain_tokens":["eta","theta","zeta"],"baseline_must_fail":true}
+{"id":"FSC-DEV-001","kind":"chain_three_hop","prime":["What does tone cause?","Actually tone causes evidence.","What does evidence cause?","Actually evidence causes memory.","What does memory cause?","Actually memory causes wisdom."],"prompt":"What does tone cause?","expected_endpoint":"wisdom","chain_tokens":["tone","evidence","memory","wisdom"],"baseline_must_fail":true,"grounding_note":"All chain tokens grounded in en_core_cognition_v1; relations are taught via priming, not pack-derived."}
+{"id":"FSC-DEV-002","kind":"negative_control_no_chain","prime":["What does tone cause?","Actually tone causes evidence.","What does register cause?","Actually register causes memory."],"prompt":"What does tone cause?","expected_endpoint":"evidence","chain_tokens":["tone","evidence"],"baseline_must_fail":false,"grounding_note":"Second priming chain (register/memory) is unrelated to the queried chain (tone/evidence); both branches grounded."}
+{"id":"FSC-DEV-003","kind":"frame_constraint_blocks_wrong_relation","prime":["What does tone cause?","Actually tone causes evidence.","What does tone mean?","Actually tone means voice."],"prompt":"What does tone cause?","expected_endpoint":"evidence","forbidden_token":"voice","chain_tokens":["tone","evidence"],"baseline_must_fail":false,"grounding_note":"Same source (tone) carries two relations (causes/means); admissibility must restrict to the causes-relation branch."}
+{"id":"FSC-DEV-004","kind":"chain_two_hop_means","prime":["What does voice mean?","Actually voice means memory.","What does memory mean?","Actually memory means wisdom."],"prompt":"What does voice mean?","expected_endpoint":"wisdom","chain_tokens":["voice","memory","wisdom"],"baseline_must_fail":true,"grounding_note":"Means-relation chain over three grounded tokens; tested relations are taught, not pack-asserted."}
+{"id":"FSC-DEV-005","kind":"chain_three_hop_precedes","prime":["What does question precede?","Actually question precedes answer.","What does answer precede?","Actually answer precedes understanding.","What does understanding precede?","Actually understanding precedes wisdom."],"prompt":"What does question precede?","expected_endpoint":"wisdom","chain_tokens":["question","answer","understanding","wisdom"],"baseline_must_fail":true,"grounding_note":"Precedes-relation chain; tokens grounded though the chain itself is taught."}
+{"id":"FSC-DEV-006","kind":"chain_two_hop_part_of","prime":["What is word part of?","Actually word is part of discourse.","What is discourse part of?","Actually discourse is part of narrative."],"prompt":"What is word part of?","expected_endpoint":"narrative","chain_tokens":["word","discourse","narrative"],"baseline_must_fail":true,"grounding_note":"belongs_to/part_of relation chain over three grounded tokens."}
+{"id":"FSC-DEV-007","kind":"adversarial_distractor_means_vs_cause","prime":["What does symbol cause?","Actually symbol causes word.","What does symbol mean?","Actually symbol means image.","What does symbol precede?","Actually symbol precedes truth."],"prompt":"What does symbol cause?","expected_endpoint":"word","forbidden_token":"image","chain_tokens":["symbol","word"],"baseline_must_fail":false,"grounding_note":"Three taught relations on the same source; admissibility must select the causes-target and reject the means-target."}
+{"id":"FSC-DEV-008","kind":"adversarial_distractor_chain_branching","prime":["What does symbol cause?","Actually symbol causes word.","What does word cause?","Actually word causes meaning.","What does symbol mean?","Actually symbol means image.","What does word mean?","Actually word means light."],"prompt":"What does symbol cause?","expected_endpoint":"meaning","forbidden_token":"light","chain_tokens":["symbol","word","meaning"],"baseline_must_fail":true,"grounding_note":"Branching adversarial: causes-chain (symbol→word→meaning) competes with means-distractors (symbol→image, word→light)."}
diff --git a/evals/forward_semantic_control/public/v1/cases.jsonl b/evals/forward_semantic_control/public/v1/cases.jsonl
index a3bbd037..e930d5a5 100644
--- a/evals/forward_semantic_control/public/v1/cases.jsonl
+++ b/evals/forward_semantic_control/public/v1/cases.jsonl
@@ -1 +1 @@
-{"id":"FSC-PUB-001","kind":"chain_three_hop","prime":["What does alpha cause?","Actually alpha causes beta.","What does beta cause?","Actually beta causes gamma.","What does gamma cause?","Actually gamma causes delta."],"prompt":"What does alpha cause?","expected_endpoint":"delta","chain_tokens":["alpha","beta","gamma","delta"],"baseline_must_fail":true}
+{"id":"FSC-PUB-001","kind":"chain_three_hop","prime":["What does tone cause?","Actually tone causes evidence.","What does evidence cause?","Actually evidence causes memory.","What does memory cause?","Actually memory causes wisdom."],"prompt":"What does tone cause?","expected_endpoint":"wisdom","chain_tokens":["tone","evidence","memory","wisdom"],"baseline_must_fail":true,"grounding_note":"All chain tokens grounded in en_core_cognition_v1; relations are taught via priming, not pack-derived."}
diff --git a/tests/test_inner_loop_phase4.py b/tests/test_inner_loop_phase4.py
index 3ff82069..bf0faa69 100644
--- a/tests/test_inner_loop_phase4.py
+++ b/tests/test_inner_loop_phase4.py
@@ -12,11 +12,16 @@ Findings recorded:
   * But globally NO STATIC threshold delivers separation_quality ≥ 0.8.
     Blade norms vary across cases (~10x range), so the same threshold
     value means different things case-to-case.
-  * The v1 chain-token outer-product blade is ungrounded in the active
-    pack — all 9 cases are skipped because chain_tokens (alpha, beta,
-    gamma, delta) are not in the en_core_cognition vocab.  This is its
-    own load-bearing finding for ADR-0025: chain-token blades are
-    unsuitable as the default region construction.
+  * Post-Phase-1 (ADR-0024 addendum): v1/dev cases were rewritten with
+    pack-grounded tokens (e.g. tone/evidence/memory/wisdom), so the
+    chain-token outer-product blade now constructs successfully (0/9
+    skipped vs the pre-rewrite 9/9).  But the chain-blade geometry on
+    v1/dev still does NOT separate cleanly (best_separation_quality
+    ≈ 0.06), reinforcing the deeper Phase 4 finding: v1/dev chain
+    blades probe teaching-driven walk (ADR-0022/0023), not the
+    inner-loop's blade-admissibility mechanism.  v1/dev belong to the
+    boundary-walk lane (runner.py); v2's seed_token + relation_blade_token
+    schema is the proper inner-loop fixture.
 
 ADR-0025 design implication: static thresholds (global, relation-typed,
 or frame-derived) are insufficient.  Per-case normalized thresholds
@@ -60,18 +65,26 @@ def v2_report():
     return characterize(cases)
 
 
-class TestV1ChainBladeUngrounded:
-    """V1 chain_tokens are synthetic (alpha, beta, gamma, delta) and
-    not present in the active pack.  The characterization should
-    surface this by skipping every case.
+class TestV1ChainBladePostGrounding:
+    """Post-Phase-1: v1/dev chain_tokens were rewritten with pack-grounded
+    tokens (ADR-0024 addendum).  Region construction now succeeds — but
+    the chain-blade geometry remains a poor fit for the inner-loop lane.
+    These tests pin the new finding: v1/dev is constructible but probes
+    a different mechanism than v2.
     """
 
-    def test_all_v1_cases_skipped(self, v1_report) -> None:
-        assert v1_report.metrics["skipped_count"] == v1_report.metrics["case_count"]
+    def test_no_v1_cases_skipped_after_grounding(self, v1_report) -> None:
+        # Phase 1 retired synthetic chain tokens; every case now grounds.
+        assert v1_report.metrics["skipped_count"] == 0
 
-    def test_v1_reports_no_separation(self, v1_report) -> None:
-        # No candidates ⇒ best_separation_quality stays at zero.
-        assert v1_report.metrics["best_separation_quality"] == 0.0
+    def test_v1_chain_blade_geometry_remains_unsuitable(self, v1_report) -> None:
+        # Constructible but not separable: chain-blade outer-product
+        # geometry produces near-zero separation_quality on v1/dev,
+        # confirming the architectural finding that v1/dev belong to
+        # the boundary-walk lane, not the inner-loop lane.  If a future
+        # change pushes this above 0.5, ADR-0024's lane-assignment
+        # decision may need revisiting.
+        assert v1_report.metrics["best_separation_quality"] < 0.5
 
 
 class TestV2PerCaseSeparates: