From my understanding all non damaging moves becoming Max guard.I feel like it'll mostly be used so Pokemon can set up without dying. Like Falinks has a move that boosts every stat it has, but it has no recovery, so maybe a D-Max HP boost will give it the time it needs to get to boost itself to the point where it can no longer take any lethal damage and begin to sweep. Though I'm not sure how boosting moves work when D-Maxed. Do they change into generic D-Max moves?