Right there is no development plan for QB’s once you go pro you are what you are and right now he is a QB has all the physical skills to play the position but makes poor decisions.
The only way to get better at decision making is being allowed to keep making decisions in football that matters.
He goes pro now he will end up just like his dad a lifelong backup. He will see action in 3 preseason games a year then struggle to be active during the regular season as someone’s 3rd QB.
Not that there is anything wrong with that you get paid a ton of $$ to run a scout team during practice but you get to keep your red jersey on and be in street clothes on game-day. Eventually he might move up to being a 2nd string QB.
I am not his life coach but he should want more for himself than that.