TL;DR: Seeking suggestions for meeting poly people IRL, as an introverted human

Seems to be that meeting poly people who are available for serious relationships, or at least not completely saturated has been more than a little daunting, to say the least, and while it wasn't really an issue for me til recently, I'm unfortunately one of those former serial monogamists who really needs an anchor/nesting partner to come home to (eventually). I can handle being solo poly when needed - personally have a few long distance partners and 1 local partner who I love to death but they're all happily married to other people, so it kinda puts a spotlight on what's missing from my own life at times, if that makes sense?

I guess what I'm trying to get at is - as a once divorced, child-free, middle aged nerd, what suggestions might this sub have for meeting poly people in a context where I know they are ENM at the very least? OKCupid was where I met my last long term hinge/primary partner, but there aren't many options since I live in a tourist town, I'm mostly getting offers for one-offs that aren't my jam, and the local community in my area seems to be highly insular and kinda reflects a lot of the things I didn't love about the BDSM scene when I was younger. I've tried other apps as well, and am very up front about not being a monogamous person - but I keep getting approached by monogamous people who think they can "convert me back" because they don't get it at all. I'm not quite at the point where I'm ready to just give up, but I do feel like the sand is moving through the hourglass faster and faster these days, and am left wondering, maybe I should just give up and take the hand I've been dealt and consider myself lucky I'm loved at all, but there's still that little voice saying.... "Whoever she is, we just haven't met yet"