Learning how to pitch at a potentially high level isn’t just about soaking it in. It’s about repeating it over and over and over effectively for many innings until it becomes unconscious habit. Doing this between now and next season along with not overextending this season and getting rest before next season will be one heck of an uphill climb.
Fortunately with my son the adjustments were about stride and drive and not arm slot. Plus he grew an inch and added ten pounds and strength to his point guard built between soph and junior year when he took lessons in the offseason.
He didn’t pitch while playing fall ball. He took pitching lessons from October to December. He rested his arm in January.
As for what level you better figure it out this fall to make plans for next summer. What kind of summer team does he play on? What level of competition do they play against? Did college coaches come to see him pitch this last summer? If so, how did they respond? Is there ongoing contact with colleges coaches who saw him pitch?
The one benefit the kid has is he’s a left handed pitcher with good physical,size. It will draw attention.. They’re the most likely to be randomly discovered. But don’t count on it. Have a solid plan.