Issues with Avastar not weighting Bento Bones

[stoplight]

Oof okay. I hate coming on here to ask more questions, but I'm absolutely stumped. Hopefully one of you guys might have an idea on what's going on... 😭

I've spent a whole lot of time making a big dragon model over several months now, and I'm finally at the phase of retopoing it because it has an insanely high polycount from detail sculpting (for, y'know, normals and textures and whatnot); and while I'm working on that, I'm realizing I have little experience with rigging and I absolutely dread it. So I pulled up some models to practice on, so when it's finally time to rig the dragon itself, I won't be pulling my hair out trying to rig this thing I've spent so long on.

Instead, I'm pulling my hair out now, lol. I've made things with nonhumanoid bodyshapes before that worked in the past a long time ago (including a tentacled floating eye thing); but now, inexplicably, weighting is just not working. The main default skeleton weights itself automatically just fine; but anything that's a bento bone (ie, tail, hind legs, wings, ect) is treated as if it's not there. I've also attempted to manually weight the bones in the tail; and it ends up acting very strange and crumpling the entire mesh despite there not being any weighting in the crumpled spots. I have no idea what's going on.

So far I've:
- made sure rotation/scale/location has been applied for the mesh and the skeleton
- toggled visibility on and off for pretty much every possible bone group and tried autoweighting with different sets
- got rid of the first skeleton I edited and edited a second one with the same issues
- toggled deforms in the sidebar menu and tried both ways
- tried weighting both with bind pose and with joints
- rotated the model to a different direction (with rot applied)
- closed all holes in the mesh
- checked version compatability with blender and reinstalled both avastar and blender
- updated(?) the rig via avastar
- probably other things I'm forgetting right now

I've been wrestling with this for several days now, and looking online for other people's advice, and I'm kinda at my wits end now. It's probably something little and obvious that I'm somehow missing, but I sure don't know what it is. If anyone has thoughts on how to troubleshoot this, I'm all ears. Thanks guys.