diff --git a/docs/setup.md b/docs/setup.md
index 30eb8c6..5d78815 100644
--- a/docs/setup.md
+++ b/docs/setup.md
@@ -206,7 +206,7 @@ Important settings:
 - `FCGI_SOCKET_PATH` is the Unix socket used for normal `.uce` requests. Set it explicitly and keep this value and the web-server `fastcgi_pass` path identical. The reference config uses `/run/uce/fastcgi.sock`; if you choose `/run/uce.sock`, use it in both places.
 - `CLI_SOCKET_PATH` is a local HTTP-over-Unix socket used by `scripts/uce-cli` and test/admin units. Keep it private (`CLI_SOCKET_MODE=0600`) unless you intentionally delegate admin/test execution to a trusted Unix group (`0660`).
 - `FCGI_SOCKET_MODE` and `CLI_SOCKET_MODE` are octal permission modes applied after socket bind. Prefer tightening `FCGI_SOCKET_MODE` to `0660` when nginx/Apache can share a trusted group with the UCE worker.
-- `SITE_DIRECTORY` is the public site tree to scan for `.uce` files. Use `/var/www/html` when the web root is outside the runtime tree; relative paths are resolved from the runtime working directory.
+- `SITE_DIRECTORY` is the public site tree to scan for `.uce` files. Use `/var/www/html` when the web root is outside the runtime tree; relative paths are resolved from the runtime working directory. Installed regression gate scripts derive their temporary test root from this setting unless `UCE_TEST_SITE_DIRECTORY` is explicitly provided.
 - `HTTP_DOCUMENT_ROOT` is the root used by the built-in HTTP/WebSocket listener when it resolves upgrade requests. Set it to the same web root as nginx/Apache.
 - `BIN_DIRECTORY` stores generated C++, wasm artifacts, compile output, and runtime caches.
 - `TMP_UPLOAD_PATH` and `SESSION_PATH` must be writable by the runtime.
diff --git a/docs/wasm-runtime-architecture.md b/docs/wasm-runtime-architecture.md
index 17e8b65..532761c 100644
--- a/docs/wasm-runtime-architecture.md
+++ b/docs/wasm-runtime-architecture.md
@@ -383,13 +383,15 @@ header free-functions are `inline`. The wasm backend exposes only declarations
   source metadata onto wasm produced from an older snapshot.
   `scripts/test_cold_component_deadline.sh` separately compiles a deliberately
   cold component that exceeds the development epoch window and proves the
-  parent request still renders it. The dependency-invalidation gate also holds
-  parent and child compile locks across a transitive source edit, proves a
-  warmed HTTP request returns the last atomically published result without
-  waiting, proves a POST returns a prompt retryable 503 without executing its
-  old mutation handler, and verifies demand-priority convergence. A CLI request
-  still waits and returns only the current dependency result after rebuild
-  completion.
+  parent request still renders it. The focused shell gates create temporary
+  `.uce` units under `UCE_TEST_SITE_DIRECTORY`, or under the installed
+  `SITE_DIRECTORY` from `/etc/uce/settings.cfg` when no override is supplied.
+  The dependency-invalidation gate also holds parent and child compile locks
+  across a transitive source edit, proves a warmed HTTP request returns the
+  last atomically published result without waiting, proves a POST returns a
+  prompt retryable 503 without executing its old mutation handler, and verifies
+  demand-priority convergence. A CLI request still waits and returns only the
+  current dependency result after rebuild completion.
   The component page also calls a parent once without its optional relative
   child and again with that child activated. This guards the component-slot
   cache invariant that a cache hit must restore both the function-table slot