We have already implemented WOT within the app which helps which such issue, having it enabled will filter out spams. The idea of having a local AI that can help with such dilemma is worth checking out.

So far I've only used client side tooling. And Yakihonne has a ton of options. But I noticed in Wisp that I didn't have to do much. I just didn't see 95% (just a guess, it's probably higher if anything) of the spam I see on other clients.