It ignores the visibility in the mixer but it follows the visibility settings in the arrangement. So it skips all hidden channels in the arrangement.
It works quiet well with the mixer since one of the later 7.0 updates. The EQ knobs are still turned upside down but this has been the case since the CC121 was released.
It works with Wavelab and Reaper too. I’ve heard that someone made it work with Jack and Ardour under Linux but I’ve not tried this myself.