hey guys,
is it possible to run a dual stage MBC (say TurboSmart) to have 20 psi for daily driving, and 12 psi for valets and stuff. also maybe when i'm in traffic and dont need all the power, or on long road trips.

the car will be tuned with ECUflash.
do i have to tune for 12 psi at all?
what are the cons of runnign the car at 12 psi if the car is tuned for 20 psi?
will it run too rich (waste gas?)

thanks!