Say when People like Van Aaken do turbo conversions etc etc, does the AFM need modding?

Say if you could add the extra fuel you needed on boost via a 5th inj or somthing, is there any problems with the AFMs not liking boost and shutting the engine down?

I know this is the case on some cars (turbo and non-turbo cars that have been converted) where it senses over a certain amount, shits itself, thinks its an error as the car should never normally get that much airflow, and goes into limp home mode or just cuts the fuel all together.

How can you stop that happening IF it happens? Ive heard of "fuel cut defenders" or whatever, that stop the above i think, but think thats only on certain cars, not all, is it?

Anyone got a clue how these shoddy conversions work?