Metahuman Machine Learning Bone-Muscle-Skin-Clothes GDC 2023

Hey gang,
I saw the live demonstration of Metahuman’s new simulation compression methods using machine learning. They showed how a linear skinned rig could sample from a pose database on the skin level of the simulation. My question is how would you set it up if you wanted to peel back the layers and have real time muscle and skeleton deformation on the same character? Would you need the linear skinned rig to include the skeleton, muscles and skin as a regular deformation rig (skin weights etc) and then have a pose generator that handles all 3 at once?