i have not seen any one use this on a rocket. i would think the problem would be when you shift even though you back of the throttle the nitrous would keep revving the engine. and if you keep appling it every time you shifted that might be a problem.
now if you hooked it to 3rd or 4th i think it would be awesome.
because of ign switch current flow on the rocket i would use a ford solenoid to draw load from bat and use a switch for the solenoids that is near right grip.
also if it ever back fires it double over the throttle plates then it goes full throttle. if you try to start after a back fire it will go full throttle.