So, how many lemmynsfw.com communities have you blocked?
I just reached 112 myself.
I'm very much awaiting a time when users can block specific instances. I still don't want to check the option to hide NSFW content, because I do want to see NSFW content that may show up on non-porn communities. Just not really interested in seeing so much porn in All.
You can check on your settings page, btw, in the Blocks tab - count quickly with Ctrl+F.
I don't really block unless it just becomes overwhelming on the TL with spam or weird comments; but my instance isn't federated anymore, anyway (though I'm not entirely sure how the whole concept works because I can still see the two I'm subscribed to fine - maybe it just won't actively show up on the timeline but you can still enter the community by typing it in??)
As far as my understanding goes, you can still see all content from lemmynsfw that predates the defederation, but you won't see any new content posted to it.