Maybe burggit.moe? They're defederated by the bigger instances because of loli hentai.
Other than that and lemmynsfw, the only NSFW instances I'm aware of are pornlemmy.com and lemmyf.uk. Pornlemmy is specifically focused on vanilla. I'm not sure what exactly lemmyfuk has. It really annoys me that none of these instances show anything if you aren't logged in, not even a list of communities. Yes, I know it's a limitation of the software.