So, I think you have other challenges than the two-way question. If he isn't going to work on his hitting to get to the next level, I think possibly he is focused on other things. Some of the better high school hitters I've known in our area hit at least a 100 balls off of a tee everyday including vacations. These guys transitioned quickly to college baseball.
Agree with CTBBallDad. I'm not big on the two-way player "thing" at showcases unless he has exceptional eye popping skills. Son was a two-way player in high school, but a starting PO on his national travel team. Every travel teammate went on to play D1 baseball so they had an abundance of bats in their lineup. They'd throw my son a bone now and then to pinch hit as a lefty hitter. There were a few position guys on his travel team that burned some mound innings (typically two pitch-pitchers...FB and CB or slider) early in the tournaments. Some of these guys thought they were two-way players when they went to showcases, and I think it diluted their exposure. For my son it was very clear when he went to showcases, he was a PO. In college it was very clear he was starting PO, although it did chap his a$$ that he thought he could hit better than some of the position players...but that is a universal thought for many college pitchers. ;-)
As a 2022, I'd give it some time to see where this takes him. Keep in mind, it probably is a decision that is coming soon if he just relies on his athleticism to carry him.
Good luck!