An additional idea (most probably beyond the time available to develop): build into the touch-Lua, the ability to create 'several' touch-zones, say, 4 on the left and 4 on the right, eg zone_L1, zone_L2, zone_R1 etc.
These zones to be able to sense long press would be great as well.
These zones to be configurable in Lua, eg like the current menu get/set arrangement.
Such zones would have some UI control, eg colour and text.
Such an enhancement of the touch UI would, I believe, really add to the touch cameras interactivity, especially the button poor EOSM.
Just some thinking.