People forget that Collie and Staley were 4.5 guys, and both were very fast. There's so much variation in handheld times that the best possible scenario gets thrown around, attached to, and claimed by players.
Speed helps for sure. To the tune of significantly increased or decreased draft stock and millions upon millions of dollars. But it isn't the end all be all. Puka didn't thrive in his 40 time and neither did Jerry Rice, the GOAT.
Roberts will need to get is 40 low enough to where it isn't a completely liability and then go kill it in everything else, then win his spot in camp. I expect a very challenging but doable path to a roster somewhere for Chase. BYU continuing to win will also help his cause.