We badly need Lemmy clients that can merge instances even if they’re defederated, as well as the other way around, filter out entire instances even if your instance won’t defederate from them. Letting instance owners dictate what you can or cannot see is not the way.
There are clients that will do the former (eg. Liftoff) but I’m not aware of any that will do the latter. I don’t understand why, it can’t be that hard to filter users and communities by instance.