Well, the times he's posted thus far speak for themselves. He'll get stronger in the coming years and I expect a huge drop in his 100M time when he matures around 20/21, as we saw from Bolt, Seville, Blake....not saying he'll break Bolt's WR's but his trajectory indicates he's headed in that general direction.
he's at the age right now where he can choose to be a 100/200 or 200/400 guy. bolt had to make the same choice as he was a phenomenal 400 runner early on.
i say he goes 100/200 because: 1. that's where the most money is at 2. knighton is only 18 (bd jan 29 2004) and likely won't hit peak bone density until ~24, which means he is going to get stronger and heavier 3. he has not fully matured from the perspective of coordination
wouldn't be surprising to see him rip a 9.75 this season with a legal tailwind.
for reference, Bolt didn't go sub-10 until 3 months before his 22nd birthday. he did however go 45.35 as a 16 yr old...good god.