FCP Plug-in compatibility on Monterey

Is there a list of which FCP plug-ins are supported / not supported on Monterey?

Probably not, not sure who has time to go testing/verifying with ever developer which are and which aren't. You can look at the web site, or email the developers of what you have to verify. But most should work in Monterey if they're just Motion templates. Anything coded, you'd really, seriously need to contact the developer.