that script gives you some millisec of advantages, from a shot to another with fingerroll, you dont have to wait untill the second finger its up to shot the next rope.
While with spacebar its one large button you have to wait the spacebar coming back and use the other finger, its another kind of timming.
Its not about fast roping, it helps you when you fail your finger timing.
Form me isnt not cheating but just a bit lame.
Im feeling cool with my spacebar i just bought the same kb i had back in the days