It isn’t that surprising to me that you received an instance ban for breaking an instance rule, even if it happened somewhere else. Users in blahaj can still see your activity, even if it’s not taking place in their instance, and a rule that’s meant to protect instance users like that one needs to apply everywhere that instance might be active. I don’t think this is mod abuse at all.

I can’t advocate enough that people have multiple user accounts for this purpose, though. The fediverse is so diverse, with so much variation in mod standards, that everyone will eventually experience this. Not as a way to evade a ban, but just as an acknowledgement that different communities don’t play well with some other communities you might be a part of. That, on top of the fact that it’s just good opsec to rotate user accounts anyway.

I don’t think anyone is going to change your mind about the specific opinion that earned you the ban, though. You seem pretty locked-in.