I don't really care about that, but given that defederation with particular instances is a good way to get a feel for what content and instance allows/disallows, it'd be nice to be able to filter instances on https://lemmyverse.net and https://lemmy.fediverse.observer and https://kbin.fediverse.observer by whether an instance is defederated or not with some list of other instances. Like, maybe you want an instance that federates with instances providing pornography (lemmynsfw.com) but not extremist political positions (hexbear.net). Right now, it's a very manual process to check the federation list on many instances.