I think just giving it as baseline to all three healers instead of a cross class skill is the perfect compromise. It's a little silly that it exists at all considering it basically does nothing, (fights are balanced around it always being on) but I understand people liking the aesthetic. Leaving it cross class is also pointless since you can already create a macro to swap it after you cast. All it does is add an unnecessary, clunky extra step that adds zero to the game and punishes newer players who don't know about swapping.