Does anyone know what the cable's max length can be by adding their extension cables - specifically the VariZoom | VZ-EXT-EX20 20' Extension Cable | VZ-EXT-EX20 | B&H 20' cable extension for the VZ-Pro-EX controller. I am wondering if I can add 3 20' extension cables.

Thanks

Considering the kinds of signals in those cables, I strongly suspect that it would work fine. But I have no first hand experience with that exact combination.