It turns out the 3BA group doesn't include some Immersive Armors meshes. They're in the Unassigned group, so that group needs to be checked when building BodySlide files.
To the best of my knowledge, these unassigned meshes refer to the ones for non-physics bodies -- they likely have no weighting for the jiggly bits on the female variants.
It turns out the 3BA group doesn't include some Immersive Armors meshes. They're in the Unassigned group, so that group needs to be checked when building BodySlide files.