won't be doing that then!
thought they only stopped the wastgate opening below what you set it at, so if the amal valve was giiving you overboost to 18psi it would still do that but would do nothing below what the boost control valve was set at
But the valve is holding back boost from reaching the actuator until the pressure you've set it to. This means that you are keeping the wastegate shut until a set pressure is reached. So, if you set it to 8 psi you will not be able to see 12 psi because the actuator would, in theory, already have opened when boost reached 8psi.
The ecu and amal valve will still control the level of boost once the valve has opened. If the ecu is saying 8psi then actuator would see 8psi, if ecu is saying 12psi the extra boost would go through the mbc, if the ecu says 3psi or it will melt your engine.....your fooked.