Two things remain for him discounting the normal physical progression we all make into our mid-twenties.
1) The hard double team and passing out of it. This also relates to catching and going. KP rarely just catches and goes QUICK. If he can master that he'll be harder to double and he'll get fouled more. Going quickly also reduces a physical defenders ability to push him and foul him on the hip.
2) Finishing with one hand. When he has an awkward finish around the rim it's often because he's trying to square with both hands. The layup at end of the game was a case of this. He needs to be able to pivot and extend with either hand. His insane length means nobody will be able to reach the ball and he'll just get his arm carved into meat.
The step through, the reverse and a traditional jump hook. 3 one handed moves he sucks at now and can improve on.
2a) I think he can shot fake even more and develop a better shot fake. People have to reach to contest and he can dribble like no 7' 3" man on earth ever has making his fake deadly.