diff --git a/.claude/skills/anland-mobilegl-plasma/reproduce.md b/.claude/skills/anland-mobilegl-plasma/reproduce.md
index 441cff5b..afa88150 100644
--- a/.claude/skills/anland-mobilegl-plasma/reproduce.md
+++ b/.claude/skills/anland-mobilegl-plasma/reproduce.md
@@ -72,7 +72,7 @@ bash scripts/build-android.sh          # -> <worktree>/build-android/libMobileGL
 ```
 The script runs, with the NDK toolchain:
 ```
--DANDROID_ABI=arm64-v8a -DANDROID_PLATFORM=android-26 -DCMAKE_BUILD_TYPE=RelWithDebInfo
+-DANDROID_ABI=arm64-v8a -DANDROID_PLATFORM=android-30 -DCMAKE_BUILD_TYPE=RelWithDebInfo
 -DMOBILEGL_PIPE_PUSH=ON -DMOBILEGL_BUILD_DISAGGREGATED=ON -DMOBILEGL_BUILD_DISAGGREGATED_INPROC=ON
 -DMOBILEGL_BUILD_TEST=OFF -DMOBILEGL_BUILD_BENCHMARK=OFF
 ```
diff --git a/.claude/skills/anland-mobilegl-plasma/scripts/build-android.sh b/.claude/skills/anland-mobilegl-plasma/scripts/build-android.sh
index 9a9c7968..164a7cb6 100644
--- a/.claude/skills/anland-mobilegl-plasma/scripts/build-android.sh
+++ b/.claude/skills/anland-mobilegl-plasma/scripts/build-android.sh
@@ -4,7 +4,8 @@
 # llvm-addr2line, it is what cyc.sh pushes).  Stamp = worktree HEAD, so the container client
 # (xbuild.sh, same stamp) and the server agree on the build ("compatible wire with different build"
 # WARN otherwise).  Env: MGL_WORKTREE, ANDROID_NDK, BUILD_DIR (default build-android), JOBS (12).
-# Log level is compiled to INFO.
+# Log level is compiled to INFO.  android-30 = the APK's minSdk: thread_local is then the platform's
+# own TLS rather than the emulated one (which cost 7-12% of an apply thread on the API 26 build).
 set -euo pipefail
 . "$(dirname "$0")/env.sh"
 W=$MGL_WORKTREE
@@ -12,7 +13,7 @@ B=$W/${BUILD_DIR:-build-android}
 STAMP=$(git -C "$W" rev-parse HEAD)
 if [ ! -f "$B/build.ninja" ]; then
 cmake -S "$W" -B "$B" -G Ninja -DCMAKE_TOOLCHAIN_FILE="$ANDROID_NDK/build/cmake/android.toolchain.cmake" \
-  -DANDROID_ABI=arm64-v8a -DANDROID_PLATFORM=android-26 -DCMAKE_BUILD_TYPE=RelWithDebInfo \
+  -DANDROID_ABI=arm64-v8a -DANDROID_PLATFORM=android-30 -DCMAKE_BUILD_TYPE=RelWithDebInfo \
   -DMOBILEGL_PIPE_PUSH=ON -DMOBILEGL_BUILD_DISAGGREGATED=ON -DMOBILEGL_BUILD_DISAGGREGATED_INPROC=ON \
   -DMOBILEGL_BUILD_TEST=OFF -DMOBILEGL_BUILD_BENCHMARK=OFF \
   -DCMAKE_CXX_FLAGS=-DMOBILEGL_LOG_ACTIVE_LEVEL=MOBILEGL_LOG_LEVEL_INFO \