Futaba T14SG is widely used and here is a way to set six-point switch for flight mode control in T14SG. I have used it in Pixhark and flight tested. It is very accurate and simple.
First go to the 'LINKAGE MENU' and select 'FUNCTION' as below.
Then go to page 2 of 4, I use channel 8 to control 'flight mode', so use the 'H/W SELECT' to set switch 'SE' as the control switch for channel 8, and switch 'SF' as the trim switch.
At the 'H/W SELECT' page, set the trim value as 30%, as below.
Then go back to home memu. Go to 'LINKAGE MENU' and select 'END POINT', as below.