Interesting on the part numbers. The prototype that Racingline was working on wasnt a shifter... it was a piece that bolts to the outside of the transmission case. I am not 100% sure how cable shifters work on fwd cars because I have never owned one until now. I am use to the shift rods that all you change is the pivot point of the shifter itself.
Here is a picture of Racingline's prototype - It doesnt look like its very complicated to make... I dont understand what the hold up is after all this time.
A true short shifter changes mechanical linkage between the shifter and transmission to speed up shifts, the external levers get shorter. Can't do it on cable shifters or trans with internal linkage like most are now.
Actually you can on shifter but the design cost of doing it is why you won't find one on a Versa, the cost is too high to make it worth it, you'll never sell them all.
A shorter STICK makes shifts faster but the stick shortened means increased force needed as you have lost leverage there, what length does.
I used to do all that stuff many many years ago on drag cars.