Looking at the clips I’ve seen from Training Camp, I’d say I see most of the issues that Carlin mentions.
One that I do NOT see is the elbow going lateral. Whatever other issues there are, getting wrist + elbow + shoulder lined up consistently can overcome other quirks and habits.
Yes, he’s definitely flexing the elbow a lot, meaning that it’s got to travel a long way, that the elbow and forearm muscles play a bigger role in the shot - and there’s therefore less steadying from the legs, spine, and shoulder girdle. It would be telling to track his effectiveness as he gets fatigued, as fatigue and contact are more likely to disturb a shot like his.
Bringing the ball over to the left is an issue for more than one reason. He partly corrects for it by bringing his right shoulder forward, meaning he’s got to do more adjusting with his wrist, etc. (so that the shot isn’t always wide left). But it’s not as drastic a move as, say, Lonzo Ball’s, and no worse than Vincent Poirier, btw, who is shown calmly sinking one corner three after another in a recent TC video.
Looking at a bigger picture, the arc of his jumper is a thing of beauty, and his touch is nice and soft, and finely tuned. Rebuilding a jump shot is a huge deal and might not pay off with results this season, but work and being coachable should get him a consistent, effective shot in the near-future.
I’m cautiously optimistic about his future; but how he fits in this season is hard to see.