I dunno that he has enough length to take on 6’6” or taller tackles. Inside against 6’4” and shorter, not engaging, rip and run is prob his best bet. With his speed he has to get inti the gap and ruin the OLs angles.
Remember Cortez Kennedy at 6' 2,3, about 287, who was probably about 270 as a college freshman, who was FAST, STRONG BOTH in college, NFL both, who was probably very much like Nathaniel James, when he was a recruit, did just fine in college, and in the NFL for the Seattle Seahawks. And he was a FORCE inside against both the pass/run. And he was able to handle 6' 6" 300 pound OL just fine.
Also Cortez Kennedy probably lifted about the same about 475 bench, 675 Squat, etc, that Nathaniel James did, does.
Cortez was a BEAST. Nathaniel is a BEAST, STRONG.
He should be able to handle 6' 6" 300 pound OL just fine, assuming he goes from 255, 260 ish to 279 to 293 while keeping both his speed, strength, while learning the right technique, leverage, etc, from Phelps.
If that happens he can, could be a beast like Cortez Kennedy someday, able to handle 6' 6"300 pound OL inside just fine.