I would argue QPR updates are functionality and subject to the 6 month test.

I would also argue a closed source release in August 2025 would start the first 6 month timer (February 2026) and the source code release to trigger another timer (if they differed in any way between the closed source release).

A lot of this law is abstract and only if the EU challenges Google's approach would it be decided how it's meant to be applied in reality.