I'm not sure it would be possible to replicate the function of the custom mode dial or to do so safely. I'm guessing if it were possible it would have been done. But even if we could have multiple custom ML settings, that would be useful.
I see this being an easily accessible menu of ML configuration presets (with camera settings too if possible). Maybe it could actually display file names, then the files could be renamed from a computer to make them more identifiable. So you select a config file from a menu and ML loads it (or maybe just restarts with it).
Can you split this request in two posts, so they can be tracked easier?
Or maybe it would be easier to create presets for ISO and WB, so that when environment changes, we could quicker pick an earlier predefined preset instead of dialing in proper WB and selecting proper ISO.
See expo presets ;)
Maybe we could have different ML settings for each C mode. I use each custom mode for something different, but I have to go back and change the ML settings when I switch.
Right now 'M' mode is not recognized by ML in a C mode, I don't think this is fixed yet (hasn't been flagged as fixed), but a set of custom ML settings would be extremely useful. If they could be saved to a C-mode, that would be even better.
Take a look here: http://bitbucket.org/hudson/magic-lantern/commits/1210bd9d89ef
You can save current menu settings as a PicoC script, then tweak it for your needs.