Unlike the GN running 11-12 AFR under boost, these engines are very efficient and running in 13s. A little deviation in the actual pressure to what the DME see may easily put it it in the 14s and you really dont want that. Of course the DME is smart enough and have at least a few more failsafe channels to protect the engine, but bottom line is you can actually loose power trying to mess with the boost. Things just doesnt work this way in the 21st century. But even when we were messing with the old turbo 745s from the 80s, they were smart enough to figure out if boost deviates with more than 2-3 psi and cut the injectors. Even if you disconnect the MAP(pressure sensor) at all.