In order to prevent strain on the cable, you might consider cable pulley from Honda CB750. It is very similar to what you are already using on your FI, except it consists of two pieces with a strong spiral spring in between. When FI reaches full throttle but you still have stroke left on gas pedal, the spring will allow pulley to further rotate, minimizing strain on the cable. It might work for you, although it will require chroming.
THIS IS ONE USED PD44A A KEIHIN CARBURATOR THROTTLE WHEEL FROM A HONDA 1976 CB750A AUTOMATIC MOTORCYCLE. ITS IN GOOD WORKING CONDITION.