Set the Source to FULL, Weight to 50, Offset to -50, and Switch to AIL. The reason for doing this is to have the value passed by the toggle (in off position) to be less than 1500 in Cleanflight, and then at ~1500 when toggled on. Since there are 3 profile options in Cleanflight, it assigns the 1st to < 1500, 2nd to 1500 and 3rd to > 1500. With these settings, this would allow Profiles 1 and 2 to be selected when toggling the switch from off to on. If it were a 3 position switch, you would want a similar set-up but want the value to swing from ~900 all the way up to ~2000 which would allow the selection of all 3 profiles. In this case, your weight would be 100 and offset would be near -100. You can play with this by changing these values and watching them on the Receiver Tab in Cleanflight.