I sounds a lot like the 'throttle cams' you can buy for dirt bikes and sport bikes. It never really alters the WOT position, it just alters the 'ramp' and how quickly the throttle blade is opened at lower throttle positions.

It also seems like the 'ramp' on a camshaft. You can totally alter the performance characteristic of an engine buy opening and closing the valves more quickly without changing lift and duration.

I'd definately want to be a try before I buy person on this.