From memory the N55 has valvetronic so probably not much similarities in the throttle logic. There's a good chance it'll have some kind of dampening between the pedal and the valvetronic operation just to create a smooth driving experience. If you want someone to dig into that you either need to offer a reward or do it yourself.
The biggest influence on pedal feel is the overall tune. If the pedal feels good when the car is on the stock map but starts to get unresponsive when tuned then your tune is the cause.