XX speed and agility has helped him survive so far, and the new ball IMHO does work against his efforts.
As of now, I beleive XX is at a crossroads and his options are essentially limited down to either 1) He can develop/strengthen his backhand and begin incoorporating it more (back around 2013, when he was ranked 1st, his backhand was the strongest and the most consistent it has ever been) - my basketball coach used to say "you are only as strong as your greatest weakness". 2) He takes his forehand to the next level and makes it downright lethal. I've mentioned this before, but I strongly feel he needs to upgrade his gear to something more powerful and explosive (the way ML did) and become a rally closer than a rally survivor.
I also absolutely agree that future penhold players will definitely have to favor more of a Wang Hao style of play. XX however, is extremely fascinating, because if anyone can do it differently than WH and still succeed, it is him. I am very interested to see the next step in XX's evolution, but what is undeniable is that it is time for him to evolve.