Well first off I can tell you this, I have 175/75's just like you. I originally installed the turbo and ran it with the 175/75's with tuning for a stock turbo. It ran great! Spool was great. I was able to peg 1500* and I once I realized that, I stopped doing it. I then went and bought an '03 turbo and put the '03 turbine assembly on the Hybrid and added a ported intake manifold and changed tuning to be adjusted for the injectors AND the turbo. It runs great!
Now, you and I can have all the exact same components and the two trucks run completely different. It's the nature of the game. I don't know how your tuning is setup. Matt tunes the Hybrid very well and Eric has done a great job with it as well.
I was just curious if you were basing your plans of getting ahold of Adrian in regards to the turbo off of something you read and not experienced. If you're having legitimate issues that can't be corrected via tuning, then absolutely call Adrian. With that being said, are you able to data log at all to provide your tuners with the parameters your truck is seeing to give them an idea of what to look for and modify?