I think that PJJ's ceiling is similar to DJ Humphries. He'll reach it earlier than Hump did and likely be more durable than Humphries (who struggled to stay healthy in college, which was a reason his draft stock was relatively low).
It's bizarre that you think QB play has some impact on evaluating an offensive lineman, but do you, bruh.
PJJ wasn't clearly the best tackle in his (historically bad) draft class as a rookie. He'd be maybe the fourth or fifth best OT in the 2024 draft class. He might make a couple of Pro Bowls if he plays a long time.
Or, he might not even start at LT this season. We'll see!