I know that that stat has just become visible, but I was wondering what is the max effect that you vets have seen.... could a 20/45 player move to 70/70?

This guys started out as a 54 overall for me https://cust33.myfootballnow.com/player/4417 and he's still getting better.

I've seen multiple players go +20-25 in a career in multiple leagues.

I've had a 7 rounder jump to a 75/75. It was a 24 point increase. I'm sure there have been larger ones.

Here are the best two from MFN-19 that I've drafted recently:

+20 CB: https://mfn19.myfootballnow.com/player/3980
+14 RB: https://mfn19.myfootballnow.com/player/4717

Both I let develop on my team and then packaged them for picks and players.