Have you tried the PDK reset? Many people report significant improvement. Not sure if it applies to your problem but free. There's a thread.

 

Yes I tried the PDK reset a few months ago at the dealership! I don't think it made any difference.

 

Hi guys, after a few weeks of driving, the solution has been tothrottle feather/light foot the acceleration with consistent acceleration pressure, as suggested by deaddog. Doing so, the shifts are pretty consistently smooth. DTE pedal box was not needed.

Solutions:
-throttle feather/light foot
-maintain consistent foot pressure on the throttle. (if I let off pressure on the acceleration and lift my foot up a bit, there will sometimes be a jerk/downshift, as the PDK will think I want to slow down/stop the car)

Thanks again for all the suggestions before! The problem was from my driving habits.