maybe we should ask what the brand and model of the atmo BOV he is using, cause I run a HKS ssqv and have none of these issues, and before you start bagging, the tuner chose to use it over the std one I supplied both were supplied to him...
I have no stalling issues with or without AC on... 21psi of boost @ 290rwkw...
the tuner did say the BOV was very surprising to him and that it held closed very well and didnt leak like most others do, that is why he used it.
maybe only some atmo bovs have given them all a bad name in some regards, not all but some problem areas...