I've been very curious about that as well. I've had two guys in the past three seasons who we're drafted as DITR candidates,and ended up becoming DITR the year of their draft. Both scouting projections (from the Amateur Draft screen) we're off the roof, so I was curious to see how accurate they actually would be.
Couldn't figure out how to post from the clipboard, but hopefully these links work.:
https://www.whatifsports.com/hbd/Pages/Popups/PlayerRatings.aspx?pid=9321084
JP Nicassio - Season 11 DITR (On my AAA team if link doesn't work)
After 3 cycles into season 13, he's gained 24/23 in hitting splits. This does not count what he gain in his initial season. 21 in glove and 25 in accuracy. For the most part these are still improving about 2 points per cycle, so I would hope this would climb up even further. His more physical traits have improved as well but not quite as much.
https://www.whatifsports.com/hbd/Pages/Popups/PlayerRatings.aspx?pid=9479668
Marv Demel - Season 12 DITR (A+ team if link doesn't work)
After 4 cycles into Season 13, he's gained over 10 points on splits/control. I can't see the prior season since it was when he was drafted, but he gained around 4 points on the end of season promotion. So all in all I hope he can progress similarly to Nicassio. Also noticed his stamina improved quite a bit (the physical trait I've noticed that boosts the most), maybe even becoming a potential starter/tweener if it keeps progressing.
I'm really excited to see what both of these guys can reach. I think their makeups and the fact that they had decent stats/made DITR is the first year is huge. For both I would hope they progress in splits/defense/control by more than 30. Hope that helps!