He needs speed and that can be enhanced.
I agree. But I'm not a personal trainer, so while I have no doubt that running in the sand with a weight belt/ankle weights and a parachute, or running full speed in waist-deep water, would enhance speed, I'm still not sure how much gain he'd achieve.
And after all that, I'm still not sure the speed he'd gain would help overcome his height in the eyes of the NBA.
On the college level, though, he is an absolute stud.
Years ago kids on my son's HS basketball team discovered platform sneakers. Amazing. A few weeks later it was almost weird to watch 6 foot wite kids dunking. Not saying that's what Dlo needs but you can develope speed and quickness with work. Maybe a pound or two off would help too. If he could show some point aptitude (he is a great passer) it would help as well.