I participated on some threads over on Space Velocity/Sufficient Battles, starting a discussion thread after some readers suggested I do so. I joke about the names because the two forums essentially have identical focuses, communities, leadership and style. I dropped some word of god and clarifications now and again, stuff that helped foster discussion and encouraged people in the fandom.
I will say that I eventually had to back off from that particular fandom. Just had a meet with some fans yesterday in Ottawa and Space Velocity came up in discussion, and others echoed my point of view - it's a very critical and somewhat entitled fanbase. They're quick to turn to criticism and rip stories apart, but they do it in a very nonconstructive way. People are actively encouraged to review things in a toxic/asshole sort of way. I got ripped into by some people there for answering questions from fans (because it invalidated their fanfiction), and personal attacks against me were common-ish during my stay there (often relegated to PM). I remember a couple of times where I'd get PMs saying, "I want to give you some criticism, is that ok?" and when I said no, that when people had to ask it was invariably the unhelpful sort of criticism, they just went, "Well, I'm going to give you the criticism anyway..." (and it was bad)
Toward the end of my visits there, a review of the opening of Twig popped up, overly heavy on the personal attacks against me and making assumptions about who I was and what I was doing; again, very much the asshole/toxic/over the top approach to criticism of a work, sometimes in an attempt to be funny, though I don't think that one was. I commented that that stuff in a review made the review suffer insofar as it wasn't balanced enough for me to find the legitimate criticism amid the attacks, and the forum moderators jumped in to back the guy and double down on the assumptions & add a few personal attacks of their own. The person who wrote the review ended up reaching out to me and saying that yeah, they were wrong, the review was overly harsh & lost something in that harshness, but the damage was done, the thread became a shitstorm after that, if you'll excuse my French, and I lost a lot of respect for a lot of members of that community/for that community as a whole as I watched it happen.
I sort of gave up on the community then, after I realized how frustrated and unhappy the general atmosphere was making me. Not something I enjoy doing, steering clear of an area where I know some of my fans are.
I say this only so that you know to take anything valuable away from that community that you can... but if you see things trending that way, don't wait as long as I did to walk away.