The Futaba radios have 2 settings for expo. One setting is when the d/r switch is in the up position, the other while in the down position. While you setting expo, flip the d/r switch. you will see the small arrow move on the corresponding channel.

Dual rates are switched at the same time as expo. They are not deactivated.

Right now I have the elevator on my lt 40 set for 0% expo when the switch is up and -15% when the switch is down. 0% is equal to the expo being "off" Haven't messed with dual rates yet.