Maybe it is more than an instance. Maybe it is an idea, a world-historical vanguard, light itself. 
actual attempt to answer (cringe)
We’ve been around for three years on a lemmy fork before federation. The lack of federation for years as well as the place we splintered off from (/r/chapotraphouse) already having a unique microculture within Reddit has given this instance, in my opinion, a distinct culture compared to general-purpose and even other hobbyist instances.
Regarding specifics, Hexbear is a vehemently queer-friendly/intersectional anti-sectarian socialist instance. Check us out 
That's strange because I'm used to being attacked for being plural and otherkin too. I mean, reactionaries have been making fun of otherkin since 2010 with that helicopter copypasta. And pluralphobia is just rampant all over the place. Barely anybody's heard of narcissistic plurality before, despite how common it is. I thought I'd be opening myself up to more hate when I talked about those things. That's how it usually goes
Well like I said we haven't had very many systems or otherkin, so some people might not understand, but like we have it/its pronouns for a reason, because it's a valid way to identify. Generally questioning someone's gender identity is strictly against the rules, and the reason that an exception was made in your case was because people confused you with a troll. You probably don't have much faith in our mods after they removed some of your comments, but I can promise it was an honest mistake, and I believe that if anyone tries to give you shit for it again, they'll remove it. They said here
As for plurality, I remember a system actually did an AMA a couple years ago when the site was pretty new, some things have changed and I think some people are more aware of it now, but it might help get an impression of what kind of responses you might encounter.
Oh that's awesome, thanks for telling me
weirdly, plurality and otherkin have explained their experience on this site at length in the past so it's a easier to understand model for many of us.
But plurality and otherkin aren't my gender. There's a lot of intersectionality but it's its own thing too. I thought nonbinary gender was more accepted than otherkin
abstractly, yes but the specifics confuse cis people I think
Yeah, it's always "I support nonbinary people" until they hear what any nonbinary gender actually is. Then straight back to transphobia, do not pass go, do not collect 200$
I think I would have been treated just the same if I were cactusgender, diamondgender, or spacegender.
you're probably right. hopefully it's better now.