Bruce
First Elevons is usually reserved for planes whose elevator functions as the ailerons as well (Delta Wing). I am not sure what your objective is with the Nexstar.

Now, if your goal is to have the ailerons to move in the same direction as the elevator, then you can mix flaps or spoilerons and the elevator. If you want the elevator to move in the same direction as the ailerons, then ailevator will work.

If you use elevons, you can get 1 and 6 to work, but channel 2 stops working because there isn't a elevator in an elevon plane.