I agree. He needs to be shown how to do certain things. He hasn't been playing high level basketball for a very long time, and he hasn't been 7 feet tall for a super long time either: he needs to be shown how to box out effectively, he needs practice using his verticality and he needs to go through the process of learning to be a 7 foot tall human being. He also needs to put on some weight: he added 20lbs in his college year, so I don't see it as impossible for him to add another 10 with a real NBA training staff and nutritionist over the next few months. That would help him immensely.
Hayes, all things considered, has looked fantastic. He recorded a career high 28 points in his first ever game, has shot 3 of 5 on jumpers through 3 summer league games (more makes and attempts than his entire time at college) and also posted a career high 12 rebounds in his first career double double tonight. The guy is just showing so many signs that he's ready to make a jump. I don't think you maximise that by shoving him in the G League and telling him to go put up dunks in meaningless games. I'd much rather give him 10 minutes of NBA action a night against backups and small-ball lineups where he isn't totally abused by 30 year old tank bigs, and can get legit run with real NBA players. After an offseason of training, coaching, and nutrition, I don't see why that would be beyond consideration.