not sure about a lot of engines but the 1.8t wont take much.
ive got the 180 version which is 0.8 bar (11.5 psi) when i put the foot down i get 11psi then settles at 10 this is controlled by the N75 valve. if i was to go over this 1800mbar limit (1000mbar = atmospheric pressure and 800mbar boost) then the ECU would go into limp mode. in other words no boost at all
with a remap the boost limits are increased.
FYI, fitting a manual boost controller to the VAG turbo is a ain in itself as you need to blank out the N75 valve.