When I first joined the Fediverse, back when Reddit 3rd party apps got nuked, I joined lemmy.world. While I didn't see Hexbear post, comments, etc., but I did see plenty of comments of people mentioning them and warning about them. So by the time I switched to startrek.website (don't remember why I decided to leave l.w, must have been due to some defederations) and finally encountered the mythical beast, I was already thoroughly prepared for it. So I would say, in general, newbies shouldn't be entirely shocked to encounter a tankie, as they are mentioned a lot.
And tbh, I prefer to stay federated with Hexbear, because among all the mindless circlejerk propaganda they will sometimes point out a fair criticism about the western culture/politics that I haven't considered. In addition, as a half Ukrainian who was living in Kyiv at the time of invasion, I prefer to know what kind of ideas and misinformation is being circulated on the other side.
Hexbear wouldn't even be that bad if they just stopped pretending that only western empires are evil, and stopped bootlicking the leaders of the pseudo-communist countries. A LOT more people would agree with them if they were only anti-western, instead of also being pro-dictators. But then they wouldn't be tankies, I suppose.
Btw, Hexbear reminds me a lot of r/GamingCircleJerk. They also have a semi-noble cause, but express it in such a way that rubs EVERYONE the wrong way, not just the "Capital-G Gamers" who they are rightfully mocking. Because of that, r/GCJ has caused several site-wide dramas and inconvenienced people. They both also operate in this constant state of maximum sarcasm, so you can never tell if they are saying is a hyperbole or they are being serious but insane.
Regarding Blahaj.zone, I haven't interacted much with them, but I one day discovered that I'm banned from their c/196 because "Transphobe". It wasn't even due to an interaction with that community directly. In a completely different instance, I think it was lemmy.world, I commented with a question about why a user's comment was called being transphobic. I then got mocked and eventually banned. So Idk if it was mod of that specific community or whole instance. I seem to be able to interact with Blahaj post from other communities though.
And thank you for these massive posts. You seem to be a proper Lemmy historian, might need to remember your username for future potential inquiries.
The communities you specified have been blocked on our instance. That's what I was talking about, they are listed in the modlog as "Removed":