I think Beehaw.org is. We’re 2/3 as well (now). .ml has some communities/users we’ve removed, but largely speaking .ml users have not caused any issues on our hosted communities, and we feel exposing them to our (generally awesome) communities is the net-positive here. Honestly .world’s (lack of) moderation is more actively an issue for our mods, but since they’re so big and we’re a niche instance we really can’t afford to de-federate from them.
Defederation is the nuclear option. Until now we had removed any communities we weren’t comfortable hosting, and treated users on a case-by-case basis based on how they behaved in our communities, which worked for a while but became untenable.
When we started this project the admin team felt that welcoming outsiders into our (wholesome, sane) Star Trek communities was the net-positive action. But as I said it became too much to handle so we unfortunately had to cut the cord.