Spectrum DX8: 2 Switches 1 TX channel 6 Flight Modes
You don’t need to sacrifice 1 RX channel to mix 6 Flight Modes out of two switches. Just mix Aux2 to itself in 3 different ways depending on the position of the F Mode switch. You need to have Flight Mode enabled with the F Mode switch.
First go to Servo Setup and set Aux2 Travel to 85%
Then go to Mixing and select Mix 3, 4 and 5 and set it up as shown in the following pictures.
You will then get the Flight Modes a pictured below. The good thing is, if the Flap/Gyro switch is in the middle (pos1) you always get APM Flight Mode 4, which you could assign to Stabilize.
So you have still the channel Rud and Aux3 free for other useful things.