I honestly feel its the opposite effect in terms of casting for me. I prefer it being on everyone BUT the tank. the tank will lose it within 5 seconds. But having it on your group can mitigate damage or even prevent one shot, if they're super duper squishy...lol but I like using it as a personal heads up. once stoneskin is gone, just to be more aware of everyone's hp bars. So if im solo healing I can shift from single healing the tank to keeping everyone's hp up.

I would like it to be an AoE Cast though, would make it less of a chore to cast