If you mean here, you did indeed say "there's no FlaggedRevs in main and Project namespace, so not much" (not sure what the "not so much" part meant, btw), so first, I assumed the namespaces you didn't mention did have FlaggedRevs, which is not the case (I don't know why you excluded templates from the survey of fully protected pages you presented there; after all, I didn't mention any particular namespaces in the original message of that thread), and second, that didn't explain why FlaggedRevs wasn't set for those namespaces. Thanks for clarifying that now.
I don't think it's a matter of "really needing" something; I presented my rationale for using FlaggedDevs instead of full protection in that thread, in a generic way: so the wiki would be more open to improvements by common editors, while still making sure that no actual damage is publicly visible in case there's vandalism. I still think that's a worthy goal, so my question is: is there any reason to not setup FR so it can be applied to pages in any namespace and then change all currently fully protected pages (except perhaps in the User namespace) to semi-protected? What disadvantages could that bring?