Sorry - I was just focusing on two different ways to define an input to drive a single servo. Combining the two different ways to show on one screen could be confusing.
If you wanted to use a switch directly as a source, use the line shown in the first shot for I5. Do not enter the lines for I6 that use MAX. Over on the mixers, link it to the servo channel(s) - channel 5 if you have just one flap servo, channels 5 and 6 if you are driving two servos. One input, driving one or two servo channels.
The second shot, for I5, shows using the same method, but allows you to play with weight and offset to fine tune where the servo arm is for each of the three positions. (there is another way, that is arguably much better, but that leads us down another path that I will avoid for now....)
To try out the second version, start over, but instead use the lines I put on I6, and skip the lines for I5. Link I6 to either ch 5 for one servo, or ch 5 & 6 for two servos.
They both end up doing the same thing, except that I5 moves flaps by using switch SA, while I6 moves flaps using switch SB.