Did an AC scout and got the response from the player. This is the quote: "I was excited to see someone from Cheyney taking in my last game. When are you going to come see me, coach? I'm sure that your guys took some good notes about my game, and recognized that I have an amazing upside to my game."

Does "amazing upside" = STL or a little below that? Or is it just "has the opportunity to improve a lot with us over the next 4 years"?

I've always interpreted that as a little below SITL - i.e. high potential.

I always figured it could be same as High Growth or maybe High Growth + to STL.
But as long as it at least High Growth AND you like his numbers, then Go For It.