Another angle on touch screens=touch focus for stills shooting.
Not really applicable to the 1DXii saga but there is a camera that will allow you to keep your eye to the EVF, right hand holding camera of course with right thumb working almost all buttons AND
left thumb tapping the screen to where you want focus. It's the Lumix GX8. You can even tap to focus and release the shutter.
This Lumix has an articulating EVF and can tilt from normal 90 degree use to straight up 0 degree use (you looking straight down). Why important? Because with just a minimal amount of tilt up
it clears an operable space for your left thumb to move about the touch screen freely without your face/cheek getting in the way.
I guess this is most analogous to camera whack-a-mole but for focus & recompose it is brilliant only helped by the instantaneous focus of the latest mFT bodies.
When one compares moving dials or even joysticks/toggles to get to a specific focus point with touch focus there is no comparison.
Well anyway just thinking out loud.
I think the touch to focus functionality works for the 1DX II when you are using Live View. However, if you shoot with the OVF on the 1D, you won't be able to reach the back of the screen with your left hand without basically letting go of the lens. Your right thumb will also barely reach the right one third of the touch screen in normal shooting position.