>>375206334
make an animation that changes the materials, make an animator that controls the animations based on a parameter, then use the avatar 3.0 component to point your lipsync visemes at that parameter instead of shapekeys

alternatively - create a bunch of planes for each mouth shape, hide them inside the head in the basis shapekey, then pull them "out" in front of the face for each shapekey and lipsync those directly
that's the old method but its not as good