Thank you for posting. I believe I have followed along correctly. Even on my 2016 ATS-V stock scan I would see the throttle closing.

Here is a stock scan.
Bruce 2016 ATSV May 22 2022 stock scan.hpl

Here is my ver 3c2 tuned scan for comparison.
2016 ATS-V Bruce 3c2.hpl

here is the current tune file 3c2:
2016 Cadillac ATS-V Bruce 2022-05-23c2.hpt

I observe that the tuned scan keeps the throttle closed, and boost [math] max is 18.4 psi (Example time 08:28:40).
The intercooler appears to be working fine.

I see still some KR that needs attention, and there is some study needed on driver demand -- I see my scan go from 109% to 92% driver demand engine torque at WOT over increasing speed in the scan for example. 08:28:39-41 which suggests the driver demand table curve is too sharp?

Also I observe that the boost in 2nd gear is less than the boost at same RPM in 3rd gear, max 16.x in 2nd and 18.x psi in 3rd. Is that the nature of the beast or does that need attention?

I would like to see more scans of other ATS-Vs.