Idk it was like 2 years ago. I just remember looking through fediverse guides and instances were labeled as either allowing NSFW content or not, no nuance. I didn’t dig into whether the specific instances were defederated from lemmynsfw nor did I even know to look for that at the time.
There’s not that much NSFW stuff that isn’t porn but I come across it occasionally. Usually jokes, sometimes people will also be very cautious and mark shit that isn’t really. I prefer to be largely unconstrained with what comes across my feed, just don’t care for the random puss intermingled.
As far as I can tell, you can only block communities in sync which is why you’re having to do it one by one. Jerboa you can just block the whole NSFW instance, one and done.