so the afc tricks the afm into thinking the boost is not too high and at the same time allows you to give the higher boost level that you are really runing more fuel to cool everything down a bit right
Your friend needs a combination of things to get past FCO. An AFM based fuel computer like the S-AFC or S-AFR cannot give you higher boost and run more fuel. The only piggybacks that can do that is the e-Manage and the discontinued VPC/FCON combo. The easiest way to get more boost safely is the Lexus/550 mod (use the search feature for more detail) combined with a fuel computer for fine tuning.
Simply slapping on an FCD on a 7m is a quick way to kill the motor.