diff --git a/loopx/capabilities/benchmark_toolkit/README.md b/loopx/capabilities/benchmark_toolkit/README.md
index 93cf6ac9f..176e6e4bd 100644
--- a/loopx/capabilities/benchmark_toolkit/README.md
+++ b/loopx/capabilities/benchmark_toolkit/README.md
@@ -261,7 +261,14 @@ release-snapshot CLI, requires the `codex_app_ssh_goal` profile and interface bu
 and proves that the returned body names that installed CLI. For an isolated case it
 also replaces the generic global-registry token with the explicit case registry.
 Keep app-server on `native_codex_profile_environment`; it supplies only the
-formal profile's `HOME`, `CODEX_HOME`, and `PATH`. The upstream provider value
+formal profile's `HOME`, `CODEX_HOME`, `PATH`, and home-scoped temporary directory
+(`TMPDIR`, `TMP`, `TEMP`). Installation and later profile calls use that same
+temporary scope, so equal-source profiles do not share runtime locators or
+shutdown ownership. Stop profile callers, then invoke
+`doctor --installation-only --restart-runtime` through its installed CLI with
+`native_codex_profile_environment(profile)` before removing the profile; require
+`stopped` or `not_running`, leaving incomplete shutdown visible.
+The upstream provider value
 must remain in `serve_runner_owned_provider_gateway`, while app-server receives
 only the loopback gateway URL and a fixed non-secret sentinel. On Linux, place
 app-server inside `native_codex_isolation` so its fresh PID namespace and
diff --git a/loopx/capabilities/benchmark_toolkit/native_codex_profile.py b/loopx/capabilities/benchmark_toolkit/native_codex_profile.py
index d853e50a5..d499179c1 100644
--- a/loopx/capabilities/benchmark_toolkit/native_codex_profile.py
+++ b/loopx/capabilities/benchmark_toolkit/native_codex_profile.py
@@ -202,6 +202,9 @@ def _formal_install_environment(
     env.update(
         {
             "HOME": str(paths["home"]),
+            "TMPDIR": str(paths["home"]),
+            "TMP": str(paths["home"]),
+            "TEMP": str(paths["home"]),
             "SHELL": "/bin/sh",
             "CODEX_HOME": str(paths["codex_home"]),
             "LOOPX_PYTHON": python_executable,
@@ -240,6 +243,11 @@ def native_codex_profile_environment(
     env.update(
         {
             "HOME": str(profile.home),
+            # The Effect runtime locator is temp-scoped and content-addressed.
+            # Equal-source profiles must not share its writer or stop owner.
+            "TMPDIR": str(profile.home),
+            "TMP": str(profile.home),
+            "TEMP": str(profile.home),
             "CODEX_HOME": str(profile.codex_home),
             "PATH": f"{profile.bin_dir}{os.pathsep}{inherited_path}",
         }
diff --git a/tests/capabilities/test_native_codex_profile_skill_versions.py b/tests/capabilities/test_native_codex_profile_skill_versions.py
index 9da0b58d6..4889bc532 100644
--- a/tests/capabilities/test_native_codex_profile_skill_versions.py
+++ b/tests/capabilities/test_native_codex_profile_skill_versions.py
@@ -2,6 +2,8 @@
 from __future__ import annotations
 
 import sys
+import json
+import subprocess
 from pathlib import Path
 
 import pytest
@@ -11,6 +13,7 @@
     NativeCodexProfileError,
     inspect_native_codex_profile,
     install_native_codex_profile,
+    native_codex_profile_environment,
 )
 
 
@@ -37,3 +40,41 @@ def test_profile_compares_skills_with_its_own_runtime(tmp_path, monkeypatch):
     )
     with pytest.raises(NativeCodexProfileError, match="loopx_version_mismatch"):
         inspect_native_codex_profile(profile.root, require_clean_source=False)
+
+
+@pytest.mark.skipif(sys.platform == "win32", reason="POSIX release profile installer")
+def test_equal_source_profiles_have_independent_runtime_shutdown(tmp_path):
+    source = Path(__file__).resolve().parents[2]
+    profiles = [
+        install_native_codex_profile(
+            source, tmp_path / name, require_clean_source=False,
+        )
+        for name in ("first", "second")
+    ]
+
+    def doctor(profile, *args):
+        completed = subprocess.run(
+            [str(profile.cli_bin), "--format", "json", "doctor",
+             "--installation-only", *args],
+            cwd=profile.root,
+            env=native_codex_profile_environment(profile),
+            capture_output=True, text=True, timeout=30, check=True,
+        )
+        payload = json.loads(completed.stdout)
+        assert payload["ok"]
+        return payload
+
+    try:
+        assert profiles[0].source_revision == profiles[1].source_revision
+        for profile in profiles:
+            assert doctor(profile, "--deep")["typescript_control_plane"]["ready"]
+        stopped = doctor(profiles[0], "--restart-runtime")["effect_runtime_restart"]
+        assert stopped["status"] == "stopped"
+        assert Path(stopped["info_path"]).is_relative_to(profiles[0].home)
+        other = doctor(profiles[1])["typescript_control_plane"]
+        assert other["runtime_lifecycle"]["state"] == "running"
+    finally:
+        for profile in profiles:
+            assert doctor(profile, "--restart-runtime")["effect_runtime_restart"][
+                "status"
+            ] in {"stopped", "not_running"}