[_paralyzed_]

spinning without the clutch engaged would be a no load situation, and motors heat up very fast with no load, as all the excess energy is disipated as heat, also, having current constantly flowing through an esc just sounds bad to me. If they are passing current they are meant to be moving for cooling airflow. Thethrottle trim is basically the same idea as yours, just without the motor spinning. Adjust it until the motor just starts to spin, then back off 1 percent so the motor does not spin at neutral.