No, cylinder pressure has a much more dramatic affect on detonation than static compression. You should be having trouble on 91 with that much cylinder pressure. I'm questioning the new gauge.
I am with you I dont trust the results.
I have made the decision to DRIVE THE CRAP out of it and no longer worry about it. If it fails I deal with it then.
This engine has approx 5000 miles on it in its current configuration.