Have seen him more like an athlete/RB learning to play QB - really didn't and still doesn't have the passing skills that would make him effective against good college Ds (*). However, he has vastly improved (saw him in person in his first game) and hopefully will continue to do that for this season so he is there when needed. As noted in the thread a position change may come for his last season of eligibility.
There are a lot of QBs have played on teams that use spread offenses before they got to HS - if this case it's possible that the number of passes thrown in their careers has a much wider gap that just what happened in HS. In the context of the thread that could mean a lot more developed muscle memory plus experience in seeing the field, etc.
Also would not be surprised to find that his HS offensive system was less pass oriented than the other two and would love to know for each how many pass plays were actually called. Am suspecting a lot more of his plays ended up being runs for plus yardage.
*See QB effectiveness being talent plus what the other 10 players can or cannot do. Think this year the expectation was the tall wide outs could get enough separation that we could throw deep along the sidelines which hasn't happened so we needed someone better at distributing the ball and appear to have found him.