The teeth certainly aren't helping anything, and something has to make a decision not to render them somewhere, and they're wasting disk and RAM if nothing else.

Also think that's a distraction from my point, so just pretend I wrote "100,000 vertex logpiles" instead of teeth.

The teeth are just the most obviously useless unoptimized thing they shipped that nobody had the time/will to cleanup before launch.

But they are also using LOD... as per your article [0]. So it's quite possible (you have the source, go look) that they call this lib with the vertex buffer of the mesh in question and get back an LOD3 mesh that's decimated and simplified but with the projected UV's. This is kinda how Unity wants folks to do "AAA" in Unity. Use a high resolution model and decimate LOD's in real-time like Unreal Engine does. Only, it doesn't work half the time. It requires that the original high poly mesh be properly UV wrapped and not vertex shaded. So to further throw gas on the fire. It's entirely possible instaLOD is the source of a lot of these issues. Combined with what you found in the rendering stages.

[0] https://instalod.com/