Use zoom rocker to control focus?

[AAtwood]

I own a compact pro camcorder, a PXW-X70. The single lens ring is an electronic one that can be toggled to control zoom or focus. The frustration I have is that I enjoy using it for zoom, but when that's assigned, there is no other way to manually control focus. Which made me think that it would be great if I could toggle the zoom rocker's function just like the ring. Having the rocker set to control focus seemed intuitive to me, push forward to focus away and back to focus closer. Since the focus is electronic in this camera anyway, wouldn't it be relatively simple to make some adjustments in firmware to do this?
Is this idea completely crazy? Has it been done before and totally flopped for some reason I'm not able to see? For a fully feature camera, it isn't all that necessary maybe, but for the compact ones, it would be amazing. At least in my opinion it would. Thanks for any input.

[marcuswolschon]

Sorry but the LANC protocol itself has a dozen commands to zoom at different speeds (++++,+++,++,+,-,--,---,----) but only 3 commands to focus ( +, - and auto).

So unless you send the "focus+" or "focus-" in different repeat-rates, it won't be a smooth rocker as with zoom.