Yeah I'm also interested in seeing how all of these sites work and looking at ways I can help improve it. The whole positing process / propagation process seems pretty complex though so I'll probably let the more familiar devs work on it for now.
From what I understand though, each admin (for example kbin.social) is maintaining a fork of their project so they could implement automod on their own local content, but that wouldn't stop propagated content (e.g from Lemmy) coming in that's spam.
Seems like the issue might need to be fixed on a site by site basis.