What you are doing is introducing atmospheric air which contains a LOT of O2 (as opposed to exhaust, which doesn't), this means you are raising combustion temperature as well as upsetting fuel/air mixture. Or so it would seem to me. I don't see how this increases performance. Why not just put in my disable switch for those times you want quicker response?
I know, that's my intention, more clean air, less hot soot, the engine can take the increased temps when tootling along, just as it can when its driven hard. Fuel / air mixture will be sorted when I get to the tune, for the moment though, I only feel the benefits, I have seen no indication of any negative affects. But I will update if that's the case.