RE: Need a Sceadu Evo 30 settings
Well let's make sure we're not using Expo and D/R interchangibly.
D/R (dual rates) is USUALLY a reference to the amount of throw (the distance the servo arm) is allowed to move as a percentage of the total possible movement to each side.
Expo refers to HOW the servo reacts to control inputs from the sticks, adding (in futaba terms) negative expo 'softens the feel of the sticks around the center of their movement. In other words if you move the stick very small amounts around the very center of their "0" position, the control result on the servo will be smaller than would normally be expected. Expo will allow the same total movement end to end but moves a very small amount in the beginning of the control movements, and a lot towards the ends of the control movement. Think of it as making the controls more progressive than linear.
USUALLY, D/R and Expo are set separately, so if your menu says 100 and 50, that probably refers to your low rates being 50 and high rates being 100.
Exponential is probably a different menu, I don't have a DX6 in front of me to be able to say for certain...