You can set VTEC On/Off based on TPS, load, and RPM. The different On/Off values give you the ability to play with hysteresis.

I've had the Apexi Neo before, and now I'm on series 2. The standalone will obviously give you more flexibility, and if properly tuned, will yield more gains. You'll see gains in the mid-range if you lower VTEC and advance ignition timing. Also, if you have wideband O2 feedback, you'll be able to dial in your AFR.