Yes it’s nothing permanent, just something you run with Cubase if you want to… I just tried it again now and it seems to work OK in 7.06, I never had any stability issues when using it.
i haven’t used it much lately myself as my usual workaround is having a button on my mouse assigned to turn off/on the mixer view so I can see those windows which have become hidden under it.
i quite like the C7 mixer approach, (notwithstanding those horrible channel name visuals in 7.05) and i am usually happy using the Steinberg compressors and gate which are so quick and easy to access on the rack, so I find it helps my own workflow overall, but this issue of things disappearing under the mixer is annoying, I agree.