Yes, I asked the people to inform each time that the analized player got a pop. When the player reached his potential limits just had a pop each 6-7 weeks, so it was easy to see "when" a trainee got the cap. I follow even Aristides Iktens trainings, an MVP who was the most waged player in BB last season (capped when he was close to 200k).
Its not a professional study, I used also Josefs Kas formulas to define the virtual wage of the players that got capped in middle season. After analyzyng lots of players I got this table. Its not exact, but is close, and can help the people, I think.
I also noticed some curious things, for example most of the PG had higher caps than most of the SF (both with the same potential, of course). An all-star PG can pop (without cap) when he is 50k, and I have never seen an Allstar SF that can pop when he is 48k+