SSS2k

I was going to run a VAFC to tune a very small shot of nitrous. However I began to think about it and realized how beneficial a VAFC 2 would be, I could use a daily driving map and a nitrous map. But they run about 300 bucks, and would greatly increase the cost of my nitrous system. So my two questions are-

Is a VAFC even necessary for a Zex 35 shot? I will dyno it either way, but if it runs lean, and I dont have a VAFC, I have no way richen it up.

Would it be possible to tune a VAFC 1 to the nitrous specs, then break the ground with a switch, so when switched "off" it would simply run off the ECU, then "on" it would modify the signals and run richer for the nitrous?

Thanks.