Hi Arin,
I just spoke with Pat at Level10 transmissions regarding options for upgrading my transmission in my 09 A4 Avant (6HP28AF). He explained to me that the ECU tune is responsible for telling the TCU how much force to exert based on “calculated torque maps” (I think I have that correct). He also mentioned that this particular transmission is capable of holding quite a lot of power in stock configuration as long as the tune allows it.
At the strip with my APR K04 A4 I’ve found that the torque feels like it’s being aggressively limited through shifts and is quite sluggish. Pat felt that ECU tuning is the key to getting snappier shifts and an upgrade to the transmission wasn’t required.
Would you be able to comment on the this ECU/TCU process and if there is any room for optimization in the APR K04 B8 tune? I’m well aware APR is more on the conservative side of the spectrum but is there an opportunity for adjustment?
Currently at 13.18@104.5 and this is keeping from 12’s in my 4000lbs grocery getter wagon 
Thanks for your help