Yeah, the primary instance (lemmy.ml) isn't the best.

I use mander.xyz, it's science focused, but they also have a policy of only de-federating instances that host CSAM.

Isn't the biggest instance Lemmy.world? I thought .ml was the oddball fringe dominated by tankies.

Where is that policy located? I could not find it.

Their /instances page also only shows a single blocked instance, whereas something like programming.dev shows lots of questionable instances blocked.

Honestly, I couldn't find it either, but the owner talks about it in his post about blocking threads https://mander.xyz/post/1062661