It is not necessary and kind of a waste to use high speed digital servos. The throttle response on all engines I or beta testers have worked is slower than a standard servo. If you use a fast servo and have a very fast or slow throttle response you may have to using a timing setting other than 2 for glow or 4 for gas. Fatory default is 4 for the timing curve that is programmed by rotary switch position 4. The only downside to have the device set too slow is time to sync is longer than it could be. However setting it too fast will cause throttle oscillations.