I think thats a little excessive, as servo boards are mini speed controllers, just closed loop (which its entirely overcome-able). Spped Modding servos seems to be more of an art than a science. It just needs playing around. Last year at debs I sped up my servos 3:1 using lego gears from the output shaft- considerably stronger than taking other gears out of the gear train. It was however more bulky. As you mentioned, take it to some of the ant folks tomorrow and see what they can do.