nope....you cant cahnge a powerband that mich without changing cam profile, electronics can do alot, but not alter the peak potential of an engine.
The point of a higher rev limit comes in handy when you need ot hold a gear longer. IN terms of acceleration yes, you will proably be better off shifting at the optimum rpm. But, if your mid corner and you need to shift up, its not great for balance of the car, and short shifting before the corner is nto always so nice for times. SO, holding on for those few extra hundred rpm means ot get can round the corner without shifting, and you dont need all that much power as your already in a corner and the main factor will be traction.