Is it possible to create RaceMenu sliders to select additional headparts?

[Mud]

While working on the MMD Anime Race's files, we seem to have accumulated a number of hair headparts that would benefit greatly from being able to be chosen independently from the actual hairs. In addition, I'd very much like to add support for animal ear sliders to the race, as what's an anime race without animal ears? Trouble is, there doesn't seem to be any resources I can use to figure out how to do this, if it's able to be done. As far as I can tell, the existing RaceMenu plugins seem to all involve either scaling nodes or adding textures instead of selecting new headparts, so there's nothing I can use to glean how to do this by following someone else's example, if it is possible. Is there anyone knowledgeable on the material who could throw me a bone over here?