Title. It's literally in their name.

Plus, very few mods use that slot so it would help populate it.

closing as curios compat was added in later versions, see #1082. Since we don't support 1.12 anymore that's all that will be done in regard to this.

Pretty sure they currently can go into any bauble slot? I might be wrong.
Or do you mean strictly have them be the charm slot only.

Yes, make them only go into Charm slots.

They work with any slots right now, and I think it's just odd since they're called "charm of X"

Just as a note: since 1.16 no longer has Baubles and Curios appears to be the replacement mod, it would be best to look into that. Whether Curios has similar slot names, that'll have to be a part of that look.