Quick questions have you tried checking split by group on the import? If I remember correctly Fusion exports part ids as groups. I could be wrong about that.
As a rigger, just a side note: you don’t have to have separate objects to animate if you’re using a rig. As a matter of fact having the separate color materials coming from Fusion or even assigning them manually in blender makes it easy to assign to bones quickly. Select object, shift+select armature, ctrl+p with empty groups. Then select the object and tab into edit mode.
1. while in edit mode press ctrl+g->set active group->Then select the bone name you want to assign the faces to.
2. Select a face that has the material of the piece you want to assign to the bone and press shift+g->Material.(This selects all faces with the same material).
3. Then press ctrl+g->Assign to active group.
Repeat 1 thru 3 for the next bone.
