We can debate 4.5 vs 4.38 all you want; having run both of those times I realize that the difference between them is all about your start. Acceleration is important, but 40-time starts don't always translate to speed in and out of your breaks. Sometimes it does, but not always.
What I see here (about 46 seconds in) is velocity. He beats the safety to the corner even though the safety had a (slight) angle. It's not world-class speed, but he's not a world-class guy. But while world-class speed is nice, if it grew on trees, everyone would have it. Watch this clip:
Here (1:46) you see him beat one-on-one coverage (against Virginia Tech, mind-you, who has produced some NFL CB talent):
Again, he's got nowhere near Marquis Goodwin's speed. But I want to reiterate just how bad MG looked in the 2019 highlights I watched. MG looked stiff, ran poor routes, and had hands of stone. At least based on the 2019 footage I saw.
Back to Dazz Newsome, he catches the ball very well, seems tough enough, had
enough speed to win many one-on-ones. He definitely looks faster than Wims.