They close the Amal valve, dropping the boost on a stock car to around 3psi.

There is no staged boost control like you were saying in your first post, and the chip does not set the boost level, 99% of MFI RST chips have no overboost protection at all and allow for unlimited boost levels (in fact thats all they do!), controlled by your actuator preload and what you bleed off (bleed valve, EBC, etc).