OK, I see. I know that this is again probably not the solution that you wanted, but here goes: get two nice MPX or Hitec digital servos and program one of them reversed then Y them off.

Another solution: Eddie has flown his Isos from day one with eight channels. One trick he uses to accomplish this is that he runs his retract valve and brake valve off of one channel. When the retract valve/servo is in the down position, it travels further in that same direction to push on the brake valve, mixed with elevator. Very ingenious and frees up a channel.

Wait a minute. By my count, even if you have both aileron servos, both elevators, and nose gear/rudder on separate channels, 10 should still be enough. What you got, turbine eject taking a channel???

Let us know what you finally decide. Take care.