Use the settings option to avoid NSFW stuff. This is your only effective option so far. There is a lot of further development needed for settings and mod tools. It will likely happen over time. There are too many NSFW communities to effectively block each one, and that is your only option as a user, on this instance, at the moment. You get the benefit of an “all” feed that contains all of the communities other users on this instance have subscribed to, but unfortunately, your “all” feed contains all of the communities instance users have subscribed to. The only other option is to self host an instance or join one that is not federated with instances hosting porn communities.