As Free-Fly mode screens any other control input, using a key already mapped for those would not interfere in any way.
- Legacy ID
- Go to Option menu.
- Try to map one of the key you use to move some other control in the Up direction to the "Free-Fly Camera Elevate".
- This (re)mapping will be rejected for no technical reason.
As it would make much sense to be able to use the same keyboard or joystick button to move something up, I'm pretty sure this principle could be expanded to any other modal domain where no side effect are to be expected as long as they get exclusive input control.
As a side note, is there a plan to allow the mapping of every single clickable UI symbol? Point and click is a nasty false good way to do things. I like my mouse but I enjoy more looking at TOM graphics than to those small rectangles where I'm expected to move the pointer at all times (especially NAV MIS LOC CTR are good candidates for some new mappings that would make my day (/nights).
Any keyboard, mouse or joysticks have dozens of buttons waiting to serve... and AutoHotkey would turn that into a sci-fi cockpit.