This is pretty annoying with the WHM skill Benediction, because it's advertised as an instant heal that brings the target to 100%. It's got a long animation of its own and doesn't go off until the end of it, but when you also have to wait to even start it... yeah. Lost more than one tank due to that until I got used to the timing.

Unfortunately it's something that you need to do early on in development. Fixing it now would be really difficult and have a lot of side effects, so I don't expect to see much change.