Multi Function Lock behavior on 5D3?
Not sure if this is a bug or "functioning as intended", but it sure is confusing:
Mode dial is set to one of the already registered C1,C2,C3 settings
Enter the C.Fn2 menu
Alter the setup for the "Multi-Function Lock" button, hit OK, Exit Menu
Power cycle camera
Custom Setting is lost!?
This also holds true for "Default Erase Option" and I assume other custom settings.
However if I alter these custom settings while the mode dial is in Av, Tv, M then the settings are properly retained across a power up.
To make things even more confusing, after I change this setup in Av, and then switch back to C1, C2, C3, then I once again lose the custom setting I just made in Av mode....because back when I registered the C1, C2, C3 setup previously I had not yet changed my Lock button setup.
When you register a Cx setup, it saves a copy all the custom settings in place at that moment, even if they are seemingly unrelated to custom modes (not sure why I would ever want different behavior of the default erase button based on the mode switch).
Moral of the Story:
Before registering your C1, C2. C3 setups, make sure you have the custom settings of the camera setup as you like.
Don't try to change custom settings while you are in C1, C2, C3 modes, they don't take across a power cycle.
If you alter one of the custom settings, you will need to re register your Cx setup in order for it to