Bill,
I was the person who initiated this post a while back and what I have found is that it does depend on the order in which the mixes are added. To trim my aerobatic plane, these are the major mixes that I use.

Ailevator
Flaperons
Rudder -> Elevator
Rudder -> Aileron
Throttlle -> Rudder
Throttle -> Elevator
With these mixes, I can force my plane to fly straight in almost all maneuvers.
The problem is that if you put the first pmix as a point mix then you loose some linking ability.
If you add another mix as Rudder -> Aux1 the Aux1 does not move with the throttle -> rudder mix.
If you change the order in which it is installed, you can loose your Ailevator Mix.
I need the above listed mixes. That is not an option. I have tried installing these mixes in various orders and haven't found an order that would allow me to add the Rudder -> Aux1 mix without it either not working or affecting one of the other mixes.
This is my real world application. I will say that other MFG radios will do this, but I like Futaba and how it programs. I will not change because I can use a Matchbox to work around this problem. I am pretty sure that the 14MZ will not have this problem but I don't have access to one to test it and I can't afford this high end piece of equipment.
Thank you for listening.