I don't think lemmy supports blocking instances (only users and communities)
However boost can mute instances (as well as users and communities)
I'm not sure what the difference is. But I think it's that boost will not show thing from your feed based on the mute list
Whereas setting something as blocked will prevent the lemmy servers from ever serving that community in your feed.
My current use case is I have an adguard home DNS filter that is currently blocking some lemmy servers. (eg: lemmynsfw)
I understand that it'll cut out any direct resources from that lemmy server, but I suppose since it's federated lemmy.world is acting as a proxy and thus the posts are still visible?
More generally speaking, is it possible to block an entire lemmy server at a network level? (DNS filtering or otherwise)