Here's how to set up AS3X+/SAFE using an NX10 transmitter. Start by adding a new model, set the wing/tail type, and then go into Channel Assign to assign a switch to the receiver's flight modes channel and the knob to control the AS3X gain. You do not need to use the transmitter's flight modes to control the receiver's flight modes. They are separate entities. You should use the transmitter's flight modes to control flaps. Use F-mode trim so that you have separate aileron and elevator trims in each flap position.