Sure, users are in control, if they choose to choose instance that opens their books, then should be able to do so. This causes a positive loop of openness, which is never a bad thing.
If some instance clearly states that they will use money on self interest, I might donate to them out of respect.
And you can have multiple accounts. One on non-nsfw side, and one on nsfw side. Then add both accounts to your favorite client. This way you have clean "safe" account and dirty perv account.