Great write up, I hadnt noticed it previously.
I'm revo stage 1 Boost 5. I spoke to my tuner about going higher on the boost but he said there was no point going higher than 7 without changing to hpfp internals as althouth the boost would be set higher there is no way the car would actually be running at 7 or above. The ECU wouldnt allow it. I am confused with those who are running boost 9 on stage 1 without hpfp internals, either my tuner or their tuner is talking balls!!
The most important thing (to me) is the driveability of the car!
have you tried higher boost settings? despite the fact I don't use these settings by other reasons, I can say that it didn't throw any fuel cut error, and the turbo achieves higher levels of peak boost without problems.
In this case, despite the fact the rail pressure drops, there isn't any problem to achieve the desired lambda factor.
Without testing I'm pretty sure that if you run boost 5, the rail pressure it's higher than boost 7, and also higher at boost 1, by the simply reason as if you close the tap, will raise the pressure in the pipe, and this doesn't mean that a wide open tap that relieves the pressure isn't flowing a lot of water
