@Nexxis Very late reply to this topic, but I am also having the same material issues, though I can sort that out. The main issue is that hand and fingers are not linking with the armature at all, they have weights in blender but just are not linking no matter what I do
to be really fair with you i haven't tested the face tracking myself and i barely use face tracking. [side note this had gonso so that might be the main cause that it isn't working face meshes get destroyed by degonsing it.. so face expersion might not work either] idk sorry