We all know what comments are for -- and aren't, but that guidance is, naturally, geared toward main sites, where we want to keep things clean and focused. Meta, on the other hand, is a site's "second place", with some different rules and conventions. For example, questions on main sites can be closed as primarily-opinion-based, but meta is all about opinions. There's a "discussion" tag and such questions collect many opinions. Meta is different.
Occasionally I see comment flags on metas and I'm never sure what to do with them. Setting aside things that are blatantly offensive or spam (that's a no-brainer), is there such a thing as "too chatty" or a comment discussion that should be moved to chat on meta? I am very conservative in deleting things on per-site metas (except on faq posts, which like main should stay focused).
Are there any guidelines specific to per-site metas?
I'm specifying per-site metas and not MSE because MSE seems to have conventions that fall somewhere between "main site" and "per-site meta". If the answer is the same for all metas then great, but I don't want to assume it'll be the same.