here goes mine:
djokovic’s forehand (watch the 07 us open final and its not hard to notice how massive of a change it was)
wawrinka’s forehand (no need to comment here)
nadal’s forehand
federer’s backhand '17-'18 (that one is questionable, maybe its more due to the larger racquet frame)
Federer was testing the 97in as early as Hamburg 2013, and began using it full-time by AO2014. I’d argue the technical change was, while perhaps facilitated by the larger head, not directly caused by the larger head.
maybe ljubicic as his coach innit