I don't see why you can't do as you propose. You will have to use one of the customizable mix functions. Have you called Jack Albrecht at Airtronics Technical Support with your question ? The 800 number is on the Airtronics website.

The nosing over problem with tailwheel models is very common. I just sort of cock my right thumb back, holding a slight bit of up elevator, before adding power. Then as soon as I'm at full power I release the back pressure. It has the dual effect of keeping the model from nosing over and also keeps the tailwheel on the ground until there's a little more air flow over the rudder to hold the airplane straight.

Dick