If you have a severe mis-match of grind specs between the primary and secondary lobes on a VTEC engine, your "flat spot" could be huge. Thinking worst case scenario: you could potentially have a gap so large that the engine would be unable to continue gaining RPM after the VTEC crossover.

It really is for the best to go with a slightly hotter primary lobe grind to more effectively match up to the characteristics of your secondary lobe. An ideal power band really is seamless between being in and out of VTEC, I can't understand why anyone would want a harder "hit" or a bigger step. It costs you more rev time than helps your acceleration, even though you will certainly keep your stock idle and have the potential for higher peak numbers, you also have the potential for a slower setup.