From memory I think one of the features of the SAFC is to allow for an atmo venting BOV.
Yeah here is the quote from the Apexi USA website:
" On hot-wire vehicles, the Deceleration Air Flow Correction function is capable of curing the erratic idle and stall problems associated with open-atmosphere blow-off valves on hot-wire air-flow meter systems."
Taken from here:
http://www.apexi-usa.com/electronics_safc.asp
So don't keep stalling, invest in a SAFC today. I'd also assume the PowerFC can do this as well but I've never looked into it....