Hightechrdn. I think the only thing that helped your boost was replacing the dv.. Wait, you don't have a piston type like all 2012 owners got stock ?
Yes, I had a piston type DV like everyone else with a TSI. I went with the BW EFR DV rebuild kit and made up a resistor plug, but it is the same setup as the AWE kit really. This mod is described on this and other forums. Plenty of other people have had very positive feedback on switching to the mechanical DV setup, whether it be with the BW direct replacement or a DV relocation kit.
This problem has nothing to do with turbo lag the dv is irrelivent. It also won't throw any codes so a vagcom scan won't get you any answers.
I was offering some advise on mods to help turbo spool and flat spots between shifts. If there turns out not to be an issue with the tune or HW fault, then it could be useful information.
The OP described the turbo not kicking in for several thousand RPM. Since we don't have any specific data, rpm points, etc, it could just be normal turbo lag, though 'lag' isn't the best word to use and it may be caused by a number of things besides being outside of the best operating conditions for the turbo. Tuning, weak/slow DV, hitting a soft limp mode, or just normal operation could all cause it to 'feel' like the engine isn't pulling as hard as it should, since feel is subjective.
Why are you so against using vagcom? It should be a first step to run a scan, even if it is just to rule out malfunctions picked up by the ECU. For example, my GTI will log HP fuel rail pressure too high faults from time to time, causing a 'cut out' when shifting, but only rarely sets a CEL for the problem. (changed HP fuel rail pressure sensor recently, but haven't checked whether it resolved the issue).
Unless there is already an updated tune that addresses this specific issue, the next step will surely be logging some runs using vagcom if there aren't any stored faults. Comparing actual vs commanded values should show pretty quickly whether there is a malfunction. This is APR's normal procedure for troubleshooting.