diff --git a/tests/README.md b/tests/README.md
index 4bd5cf1..a6e0e3a 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -303,18 +303,14 @@ Button positions (relative to canvas):
 
 ## Open tasks
 
-- **Research: are the Asyncify fiber shims still needed under native-EH?** Two
-  `scripts/common/inject-dyncall-shims.sh` fixes — the fiber trampoline self-heal
-  (§3c) and the nested-Asyncify handleSleep save/restore (§3) — were written for the
-  legacy-EH *park-throw* model. Under native wasm-EH the top loop is a per-frame-yield
-  while-loop with no park-throw, so ablating either shim
-  (`SHIM_DISABLE_TRAMPOLINE_HEAL` / `SHIM_DISABLE_HANDLESLEEP`, wired in
-  `tests/apps/Makefile.wasm`) no longer reproduces the disease it guarded — the old
-  red "ablation pins" in `asyncify/asyncify-races.spec.ts` have been flipped to
-  green "shim-redundancy pins" that now prove the native-EH path stays clean *with the
-  shim ablated*. **To do:** sweep the real apps (modals, nested fibers, long sleeps,
-  pthread pool) with each shim ablated; if all stay green, drop the shim injection and
-  these pins. Until proven, they stay injected (belt-and-suspenders).
+- ~~Research: are the Asyncify fiber shims still needed under native-EH?~~
+  **Resolved at doc 20 D-1** (legacy-runtime deletion): the ablation builds
+  (`races_test_noheal` / `races_test_nosleepfix`) and their shim-redundancy pins in
+  `asyncify/asyncify-races.spec.ts` pinned a runtime that no longer exists — the
+  scheduler shim (`scripts/common/shims/asyncify-scheduler.js`) is the only runtime
+  and subsumes the handleSleep save/restore; the fiber trampoline self-heal (§3c)
+  remains injected unconditionally. The green battery runs every scenario against
+  the scheduler glue.
 
 ## Collab e2e — legacy vs v2 bundles, and repro markers
 
diff --git a/tests/apps/Makefile.wasm b/tests/apps/Makefile.wasm
index 3ba1aa2..f40d4b5 100644
--- a/tests/apps/Makefile.wasm
+++ b/tests/apps/Makefile.wasm
@@ -200,8 +200,6 @@ all: minimal_test.html \
      $(S)/coroutine/coroutine_test.html \
      $(S)/coroutine-nested/nested_test.html \
      $(S)/asyncify-races/races_test.html \
-     $(S)/asyncify-races/races_test_noheal.html \
-     $(S)/asyncify-races/races_test_nosleepfix.html \
      $(S)/coroutine-pthread/coroutine_test_wxpt.html \
      $(S)/coroutine-pthread/embind_repro.html \
      $(S)/coroutine-pthread/gl_repro.html \
@@ -747,9 +745,9 @@ $(S)/coroutine-nested/nested_test.html: $(S)/coroutine-nested/nested_test.o $(S)
 	../../scripts/common/inject-dyncall-shims.sh $(basename $@).js
 
 # Asyncify race-condition red-green harness (tests/asyncify/). Three variants of
-# the same app: full shims, trampoline-heal ablated, handleSleep-fix ablated.
-# The ablated builds keep the historical bugs reproducible (red) so the shim
-# fixes stay pinned by tests. Same .o, three link+inject passes.
+# (The trampoline-heal / handleSleep ablation variants — races_test_noheal /
+# races_test_nosleepfix — were retired at doc 20 D-1 together with the legacy
+# runtime they pinned.)
 $(S)/asyncify-races/races_test.o: $(S)/asyncify-races/races_test.cpp $(S)/coroutine/kicad_coroutine_harness.h
 	$(CXX) -c $(CXXFLAGS) -I$(KICAD_ROOT)/thirdparty/libcontext -I$(S)/coroutine $< -o $@
 
@@ -757,14 +755,6 @@ $(S)/asyncify-races/races_test.html: $(S)/asyncify-races/races_test.o $(S)/corou
 	$(CXX) $^ $(LDFLAGS_RACES) --pre-js $(JS) --shell-file $(HTML) -o $@
 	../../scripts/common/inject-dyncall-shims.sh $(basename $@).js
 
-$(S)/asyncify-races/races_test_noheal.html: $(S)/asyncify-races/races_test.o $(S)/coroutine/libcontext.o $(WX_CORE_LIB)
-	$(CXX) $^ $(LDFLAGS_RACES) --pre-js $(JS) --shell-file $(HTML) -o $@
-	SHIM_DISABLE_TRAMPOLINE_HEAL=1 ../../scripts/common/inject-dyncall-shims.sh $(basename $@).js
-
-$(S)/asyncify-races/races_test_nosleepfix.html: $(S)/asyncify-races/races_test.o $(S)/coroutine/libcontext.o $(WX_CORE_LIB)
-	$(CXX) $^ $(LDFLAGS_RACES) --pre-js $(JS) --shell-file $(HTML) -o $@
-	SHIM_DISABLE_HANDLESLEEP=1 ../../scripts/common/inject-dyncall-shims.sh $(basename $@).js
-
 
 # Convenience targets
 menu: $(S)/menu/menu_test.html
@@ -836,7 +826,7 @@ $(S)/retinascale/retinascale_test.html: $(S)/retinascale/retinascale_test.o $(WX
 retinascale: $(S)/retinascale/retinascale_test.html
 coroutine: $(S)/coroutine/coroutine_test.html
 coroutine-nested: $(S)/coroutine-nested/nested_test.html
-asyncify-races: $(S)/asyncify-races/races_test.html $(S)/asyncify-races/races_test_noheal.html $(S)/asyncify-races/races_test_nosleepfix.html
+asyncify-races: $(S)/asyncify-races/races_test.html
 
 # Only delete generated app files (*_test*, *_repro*) — a bare $(S)/*/*.js would
 # also delete checked-in sources like coroutine-pthread/worker_dom_stub.js.
diff --git a/tests/apps/standalone/asyncify-races/races_test.cpp b/tests/apps/standalone/asyncify-races/races_test.cpp
index 539b415..5589152 100644
--- a/tests/apps/standalone/asyncify-races/races_test.cpp
+++ b/tests/apps/standalone/asyncify-races/races_test.cpp
@@ -411,9 +411,9 @@ private:
 
     // ----- scenario 1: post_park_fiber_swap -------------------------------------
     // The KiCad hang topology. OnInit already did a fiber swap, so the park throw
-    // went through the live trampoline. With the self-heal shim the guard was
-    // reset and this swap works; with SHIM_DISABLE_TRAMPOLINE_HEAL=1 the guard is
-    // stuck true, the Call() below never returns, and the watchdog fires.
+    // went through the live trampoline. With the self-heal shim the guard is
+    // reset and this swap works; historically (ablated heal, retired at doc 20
+    // D-1) the guard stuck true, Call() never returned, and the watchdog fired.
     void Scenario_PostParkFiberSwap()
     {
 #ifdef __EMSCRIPTEN__
@@ -608,9 +608,9 @@ private:
 
     // ----- scenario 5: long_parked_sleep_clobbered_by_swap ------------------------
     // The KiCad clipboard crash shape: a long-parked sleep crossed by complete
-    // fiber-swap cycles on fresh stacks. With handlesleep.js the sleep's buffer
-    // is restored at wakeUp; with SHIM_DISABLE_HANDLESLEEP=1 doRewind reads a
-    // clobbered currData -> "index out of bounds".
+    // fiber-swap cycles on fresh stacks. The scheduler shim restores the sleep's
+    // buffer at wakeUp; historically (no save/restore, ablation retired at doc 20
+    // D-1) doRewind read a clobbered currData -> "index out of bounds".
     void Scenario_LongParkedSleep()
     {
 #ifdef __EMSCRIPTEN__
diff --git a/tests/asyncify/asyncify-races.spec.ts b/tests/asyncify/asyncify-races.spec.ts
index 724f14f..fed63f5 100644
--- a/tests/asyncify/asyncify-races.spec.ts
+++ b/tests/asyncify/asyncify-races.spec.ts
@@ -3,12 +3,11 @@ import { test, expect, tryLoadApp } from '../e2e/utils/fixtures';
 // Red-green specs for the Asyncify race-condition harness
 // (tests/apps/standalone/asyncify-races/races_test.cpp — see docs/features/async/).
 //
-// Two kinds of tests here:
-//  - GREEN-target tests assert the desired end state (clean pass, clean console).
-//    While a fix is missing they FAIL — that failing run is the recorded "red".
-//  - ABLATION tests run the shim-ablated builds (races_test_noheal.js /
-//    races_test_nosleepfix.js) and assert the historical bug REPRODUCES.
-//    They pin the disease so the shim fixes stay testable forever.
+// GREEN-target tests assert the desired end state (clean pass, clean console).
+// While a fix is missing they FAIL — that failing run is the recorded "red".
+// (The shim-ablation builds and their pins were retired at doc 20 D-1 together
+// with the legacy runtime they exercised; the scheduler shim is the only
+// runtime, and the battery below runs every scenario against it.)
 
 const BATTERY = [
   'post_park_fiber_swap',
@@ -176,78 +175,3 @@ test.describe('Asyncify races — green targets (full shims)', () => {
     expect(unwindLeaks, `unwind escaped the park: ${unwindLeaks.join(' || ')}`).toHaveLength(0);
   });
 });
-
-// These two were "ablation pins": they ablated a JS-shim fix (via SHIM_DISABLE_*,
-// see tests/apps/Makefile.wasm) and asserted the LEGACY-EH disease came back — a
-// stuck Fibers.trampoline guard (trampolineRunning=true) / a clobbered parked-sleep
-// buffer. Under native wasm-EH the top loop is a per-frame-yield while-loop with NO
-// park-throw (docs/features/wasm-exceptions; native-EH top-loop redesign), so the
-// disease's *trigger* is gone at the root: ablating the shim no longer reproduces
-// it. (The green "battery" above already runs both scenarios full-shim.)
-//
-// So they are flipped red->green: each now pins that the native-EH path stays clean
-// EVEN with the legacy shim ablated — i.e. the scenario completes with no disease
-// signature. That keeps them as the live signal for the open question below.
-//
-// TODO(research): are these shims still needed AT ALL under native-EH-only? The
-// fiber trampoline self-heal (§3c) and the nested-Asyncify handleSleep save/restore
-// (§3) in scripts/common/inject-dyncall-shims.sh were written for the legacy
-// park-throw model; ablating either no longer breaks the scenario it guarded. If a
-// full sweep of the real apps (modals / nested fibers / long sleeps / pthread pool)
-// confirms they're dead weight under native-EH, drop the shim injection AND these
-// pins. Until then they stay injected (belt-and-suspenders). Tracked in
-// tests/README.md "Open tasks".
-test.describe('Asyncify races — shim-redundancy pins (native-EH stays clean with the legacy shim ablated)', () => {
-  test('trampoline-heal ablated: native-EH post-park swap still completes (no stuck guard)', async ({
-    page,
-    testLogger,
-  }) => {
-    await page.goto(
-      '/standalone/asyncify-races/races_test_noheal.html#only=post_park_fiber_swap'
-    );
-    await tryLoadApp(page, 30000);
-
-    await expect
-      .poll(() => findSummary(testLogger.consoleLogs) ?? null, {
-        timeout: 45000,
-        message: 'post-park swap should complete even with the trampoline self-heal ablated',
-      })
-      .not.toBeNull();
-
-    const { passed, failed } = parseSummary(findSummary(testLogger.consoleLogs)!);
-    expect(passed).toBe(1);
-    expect(failed).toBe(0);
-
-    // The legacy disease signature must be ABSENT: no stuck-trampoline watchdog dump.
-    expect(
-      testLogger.consoleLogs.some((l) =>
-        l.includes('[ASYNCIFY_RACES] WATCHDOG post_park_fiber_swap')
-      ),
-      'no stuck-trampoline watchdog should fire under native-EH'
-    ).toBe(false);
-    expect(crashLines(testLogger), 'no crash signatures in console').toHaveLength(0);
-  });
-
-  test('handleSleep ablated: native-EH long parked sleep is not clobbered by a swap', async ({
-    page,
-    testLogger,
-  }) => {
-    await page.goto(
-      '/standalone/asyncify-races/races_test_nosleepfix.html#only=long_parked_sleep_clobbered_by_swap'
-    );
-    await tryLoadApp(page, 30000);
-
-    await expect
-      .poll(() => findSummary(testLogger.consoleLogs) ?? null, {
-        timeout: 45000,
-        message: 'long parked sleep should resolve even with the handleSleep fix ablated',
-      })
-      .not.toBeNull();
-
-    const { passed, failed } = parseSummary(findSummary(testLogger.consoleLogs)!);
-    expect(passed).toBe(1);
-    expect(failed).toBe(0);
-    expect(crashLines(testLogger), 'no crash signatures in console').toHaveLength(0);
-    expect(realErrors(testLogger), 'no page errors').toHaveLength(0);
-  });
-});