Originally Posted by James @ M Developments.

it may well be a big disadvantage for drivability, and again i completly agree. But on general daily use it would be better on fuel in most cases, because of the disadvantage it has.

Using higher RPM is all part of owning and tuning a car with a large turbocharger. Which is why i would always find out what the customer wants and intends to use the car for, before specing a turbo/engine.

803 greens T3 packages will use a 3 bar sensor which covers more than enough scope for a T3.
The Boost on the T3 will always tail, no matter what you do as the compressor is so small the engine can easily consume all the air it can make at high RPM as VE increases.

The same with our 55s T34 Packages, we peak at 32psi, but from then on the waste gate is closed and the turbo runs flat out. The boost will naturally drop as the engine starts to consume more and more air, so the turbo cannot maintain high plenum pressure.
As far as safety goes, its the best way to go, you could weld the wastegate shut, and still not go lean and melt and engine, as they fuel the turbo flat out anyway.