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.
EDIT: Now that I look again, pornlemmy has applied a patch to show NSFW without login, like lemmynsfw used to do. Good on them. Still vanilla though. ¯\_(ツ)_/¯
lemmynsfw.com will definitely show communities if not logged in, and you can see everything if you open one. pornlemmy.com shows everything if not logged in. Both of these are from a web browser, and in my experience if I click on a communty from my feed in either connect or liftoff. and if you hit settings and on each instance, by default they are set to filter stuff for not logged in, you can turn that off, even if you're not logged in.
However, lemmynsfw does in fact block NSFW for people that aren't logged in. When I go there (in a web browser), the front page is full of SFW pictures of celebrities. The community list is just a bunch of celebrity-name communities, along with the occasional porn community that forgot to apply their NSFW tag. If I go to those communities though, no posts appear.
Huh. Terminal curiosity, but randomly clicking through, I saw a lot of 2000's era racist/sexist humor, mostly banning NSFW, one entirely made up of github links and anime girls, a weirdly normal Reddit clone, and... one that was suspiciously banned from the internet lol.
So, at least one person got Hansen'd. Which, I can't imagine what they thought was gonna happen there.
I feel like I heard the story of the one banned from the internet. Dude in Ireland hosted a loli instance and got his shit raided. Could be a different instance, but I do know that is a thing that happened