diff --git a/docs/implementation-plan.v1.md b/docs/implementation-plan.v1.md
index 5b36cfd..9e3fbaf 100644
--- a/docs/implementation-plan.v1.md
+++ b/docs/implementation-plan.v1.md
@@ -1035,8 +1035,10 @@ and Administrator Protection enabled when the current Windows image exposes it.
 Tests that require the interactive desktop may be a
 release-candidate gate rather than per-commit, but cannot be replaced by mocks
 or a service-account runner. Add a Server Core service/Session-0 smoke lane.
-Exercise at least the oldest supported Windows baseline and one current desktop
-release before publishing.
+For the Windows-first v1 milestone, use the provisioned Windows 10 Pro 22H2
+fixture as the compatibility baseline. Older Windows and Server validation is
+explicitly deferred to a later compatibility pass; its absence does not delay
+current implementation or native smoke coverage.
 
 Use one declared test matrix and the same harness entry points everywhere: