cory_can,
Your car is really impressive. The B8 2.0T is a real strong platform. JHM is working hard to get the B7 2.0T into a new place, Spoiler alert and keep it a secret they already broke both the ko4 and ko3 records for the B7 2.0T using a stock ko3 turbo. ON NOW, to your question.
While I canāt speak for APR, I can close to 100% tell you that their tune isnāt holding the transmission back. These ZF6hp transmissions have a lock and unlock feature in the TQ converter that will give you a pain when you get a good boost in TQ.
Doing several 6hp transmission tunes, I can tell you it helps a great amount in most cases.
Stay away from Transmission hardware changes. 517, level 10 stay away from them all. Valve body work is bad news and since itās already computer controlled, there isnāt a gain in shift speed. As for the TQ converter you can do some stuff there but you can only move the stall speed a few hundred rpm or you will get fault issues.
I responded more in a return PM to you.