My idea has always been some players shouldn't hit big improvement until their senior years, some their junior years and sure some huge growth freshmen. I think the easiest way for them to program it would be after x minutes of pt the player hits their big growth. Of course not all players should have this, some should just be on the linear path and some should be the ones that max out fairly quick. The info could be incorporated into Evals (that are now pretty useless other then using them to get players to take hv and cvs) with "Player has a lot of potential but it might take him a while to get there" or "This kid is ready to touch the sky once we get him into our program".
Also if it was done by x minutes played it would leave it somewhat up to the coach also, get your younger guys pt while they are young, it would help those that had this get their quicker. It wouldn't be hard to do, if they want a player to hit their development in their sophomore year, well then just do the simple math (let's use the average of 12 mpg for an 'average' fr and we will use 27 games, since that is also all anyone is guaranteed.) (also this would be a small added bonus to making the postseason is more pt for your younger guys, since I have always thought it is such bull that player growth stops once you finish the ct) So with that math (12x27) once the player has played 324 minutes he would hit his 'super growth' and would start to reach his potential quicker. If you wanted it to be his Junior year ( ((17x27)+324) = 783 ) so around 800 minutes the player would hit his super growth. (by the way these average minutes are totally made up numbers) Then as a coach if I wanted to get my player there quicker or had a bad team and had to play younger guys and my freshmen sg played 22 mpg he would hit his super growth stage after about 15 games into his freshmen season.