Does this actually work for you?
I tried something similar where I wanted to change collision profiles on a per bone basis.
BodyInstance->SetCollisionProfileName(<SomeName>);
But this ends up returning the main skeletal mesh’s settings for exactly this.
For example, after I try to set impulse on a bone after detaching it for a dismemberable mesh system, it fails because the main skeleton is set to the CharacterMesh profile and not Ragdoll like I’m trying to set the body part to.
It almost seems like it’s actually a bug if this works for you, but it does give the desired behavior. I want that code in BodyInstance.cpp to not exist too, but you’d probably have to modify the source and there might be some unintended consequences.