Can't really pressure test a supercharged car.

Just remove the lower hose from the bypass valve (BBV) actuator and cap it on the solenoid. Leave the lower nipple on the BBV open to atmosphere. That'll leave vacuum bypass in tact, but remove the traction control function. In other words turn off traction control if you anticipate wheel spin until you reconnect that hose.

You can go higher, but you're risking your head gaskets.

Not recommended to go much lower than 16 though.