>>290328921
>Separate materials require separate skinned mesh
One skinned mesh is ideal. ctrl+j in blender.
>Can pack multiple avatars in one scene and it'll just compile the one.
Everything parented to whatever the vrc avatar descriptor component is on will get uploaded. You can put a plane with an image in the scene and move the camera to it on upload to get a profile picture for example.
>Reasonable overall combined texture resolution
Wouldn't go higher than 4k textures but that's just unity getting less efficient the bigger the texture res is.