Yes, I agree with Espi. It's really useful when both healers are down and the party is about to wipe. I always save it for when that happens and there's no one able to res - or situationally if we need a tank up or someone up and there's no time to res.

Healing full mp/tp LB would be great too. I wish all jobs/classes had custom LBs. Seems a bit lazy on SE's behalf to not have done that.