At this point, you might find some small instances that fit that description, but as things settle down, you’ll find that what you’re looking for is impossible.

For example, I’m an admin of a trans and queer centric lemmy instance. My first and foremost goal is giving that community a safe space, in which they can exist with their guard down at least a little, where they know that they don’t have to deal with endless bigots and trolls trying to undermine their right to exist.

So, the moment I see an instance that actively chooses not to block any other instance, even if they’re full of bigots, then I am going to defederate both instances, because otherwise, I’m going to end up trying to deal with endless waves of hate from both sources.