IIRC he was 5’7’’ tall.

You are correct about Webb's height. Pretty sure he's the shortest to win the contest.
I think McLeung is the 4th shortest. Pretty sure Dee Brown was shorter.
But, none of those guys were doing the tricks McLeung did.
He not only jumps high, but his understanding of angles & take off points is superb. (Former high-flier here, so I understand).
Also, he has the ability to use his horizontal speed to load up for vertical height. His standing vertical is an impressive 44+ inches, but on that 540 dunk he got 49.5 inches off the ground.
I wish someone could have improved his shot & his defensive instincts. He'd be full time in the league if they did.

He certainly can improve his shot. He can add a step of range, improve his accuracy, but his biggest need is a quicker delivery. He takes too long from commitment to release. He doesn't have to be Curry, who does it in the blink of an eye, but needs to be quicker.
He's spent his whole life being able to get to the rim any time he wanted, so these things weren't needed, hence never learned.
On the D side, however, I have greater concerns. He, like other pro prospects and even NBA guys (Ben Gordon comes to mind) has horrible defensive instincts. He doesn't anticipate well, he gets lost on screens, and he's not strong enough to fight through them. It's not lack of effort. He's not a lazy defender. He's just bad at it.
Gordon never got better & it shortened his career, and he WAS a shooter who create his own space.
This concerns me greatly about Matt. With his offensive attack game, he'd be 9n an NBA team right now in a full contract. But, he's not. It's not useful to score 25 then give up 33.

Hope he can make it into the NBA.