Multiple Bodies Per Bone?

I know you can have multiple shapes per bone, but is there no way to have multiple bodies per bone on a physics asset? I wanted to define different physics materials for different collision primitives, think like a metal hat on a meaty heat, both on the head bone. I don’t want to have to add more bones to the skeleton just to get around this limitation, but since the physics materials are stored at the body level and not shape level, I’d really like to be able to create multiple bodies on a single bone.

Anyone know if that’s possible? The option for Add/Replace bodies seems to be limited to 1 body on a bone.