I also have a dxe, haven’t used it in a while though. No, you can’t do a mix with it to do differential thrust. But, (fortunately) you can get a V-tail mixer from hobby king for about 3 bucks. Plug one esc into one port, the other esc into the other port. Then plug one lead from the mixer into throttle on the receiver, the other into the rudder port. Test and see if it works properly, if the differential is reversed, swap the two esc leads. If they are messed up ( don’t spin properly at the same speeds) reverse the mixer leads at the receiver.