Sure, you have to sign up for it but you can’t remove the hardcoded crypto wallet extension and therefore can’t actually opt-out of having it shoved in your face (at least, it was the time i tried their browser and found it to be inferior in every way to just using Firefox and uBlock Origin).
This tracks with my previous attempts at reporting that Sinfest guy. Posts hundreds of comics that blatantly break multiple official substack content guidelines and I get the effective equivalent of a promise for “action” combined with a dismissive eye roll. They completely ignored my follow-up email detailing the complete lack of action and the dozen or so new content guideline violations.