Complex Mixer "None", for the 1st, why?

I was reading Matthias's Complex Mixer Tutorial, He mentions this, which is what I see in some of Tom Z's configs I loaded.

IMPORTANT: If you want to assign one or more different curves to a mixer and control them with a switch, say e. g. the FMODE switch for two or more throttle curves, make sure to select "None" for the switch of the FIRST mixer on PAGE 1.

Why? Why should I use "NONE", instead of "NORMAL", when setting up Mixes for the FMode.

Or what would occur is "NONE" isn't selected, what cause and effect would I see?

Thanks, sorry for the newbie question.

Since no one has answered it, I will:

The switch needs to be None. While that's not strictly true, doing it that way will be more robust.

Consider what happens if you have a 1-page complex mixer. If you have a switch of FMODE1 but the switch is set to FMODE0, what's the output? Now extend that to a two-page mixer on the Devo 7E, with settings for FMODE0 and FMODE1. What happens when I move that to a different transmitter that lets me set things to FMODE2?

Setting the first mixer switch to None establishes a default value for the channel. You then modify and/or replace that with further mixers. So instead of using FMODE0 and FMODE1, you use None and FMODE1. It behave the same way on a 7E, but will not have odd behaviors on other transmitters or if you should edit it later for some reason.