The kill switch works by moving the servo a little more beyond the lower limit you have set in your EPA. My way is to get the engine at a good idle using the EPA with the trim in the middle. That way I can tweak the idle as it changes due to weather using the trim. One other thing I do that hasn't been mentioned yet is I give the servo more throw on the top half of its travel than on the bottom. If you set it up linear you won't actually get a linear throttle response RPM wise. It will be more sensitive on the bottom than on the top because throttle response is exponential, not linear. Pilots who just set it and forget it won't care, but I do work the throttle a bit during maneuvers. My 40-60 size glow engines do well with about 50% more travel at the top than the bottom, so a typical end point adjustment would be 80% on the top and 55-60% on the bottom for me. At mid stick, that puts the servo arm 10-15 degrees pointed away from the carb when a straight linear setup would have it at a perfect 90.