2014 Ram 3500 - Turbo Pressure Going Blank

I have a 2014 Ram 3500, Aisin, bullet proof, heater-grid delete, FASTSD07165G fuel system, S&B Cold Air intake, 4" Pusher Intake, upgraded head studs, and now a Fleece Cheetah turbo installed.

The truck runs like a scolded cat when I'm not loaded. When I hitch up to my 40' 5th wheel, I can feel the increased power and performance and I run the tuner on 1, until I'm at highway speed with the engine temp normal, and I'll switch it to 2, when I'm not expecting numerous long or steep hilll climbs.

The only problem I'm experiencing is when I'm on steep, long-grade climbs, and I'll do these mostly in Mode 1 (stock w/delete) and no extra horsepower. The truck combination is running at just under 14 Ton with the hitch up. The climb will start out fine, but when the truck downshifts (which I normally do manually using the top gear lockout just before reaching 1,500 RPM), the turbo pressure will adjust, and I'll continue the climb with no issue. As the turbo pressure continues to rise, it will max out around 34+ psi before the display on the EVIC and RaceME Ultra display goes blank.

So, Fleece is saying that's because the stock sensors and ECM aren't expecting to see anything above 35psi under factory conditions. Check...makes sense to me. But what does that mean for the ECM controlling the new VGT Fleece Cheetah? Is the ECM and sensor pairings limiting the Fleece to < 35 psi of performance to match stock parameters? Even worse, will the ECM send a message to the VGT controller to reduce turbo pressure because it's seeing a value that's too high for stock parameters?

I currently set up the RaceME Ultra to display the commanded v. actual VGT position, which is what Fleece asked me to look at for now. I doubt I'll see the issue crop up until I'm hooked up at the end of February, but even then, I'm towing across flatter sections of TX with minimal chance of pushing the turbo pressure beyond the 34-psi threshold where I'm experiencing the issue.

I appreciate any suggestions from the forum. I'm really at a loss because I'm not sure how the flow from the intake horn sensor, to the ECM, to the VGT components interplays and where the true issue may lie.