Tbh I don't think changing cap is necessary.
I was drafted like 4th round and I'm in top 20 of TPE earners of my class. I'm 550 TPE and I'm getting called up.
Why? Cause Team needs me. I would happily stay down if Team didn't need me and I could have gone up with 650+ TPE

SHL GM's want players to get as much TPE as possible. For Example, EDM Prospect will probably stay down for 4-5 Seasons just because they have so many High TPE players.
Sometimes you go up at 550 TPE. Sometimes 700 TPE