Hallo Gradskater, I used to use my CV Meter on a Zorki Mir (like Zorki 4). I had to use a piece of paper underneath the meter as the accessory shoe wasn't a tight fit, nothing of great concern as I have to do the same with my Leica IIIa.
As for the winding knob obstruction, I've had a look at some photos of Zorki 6's and this may be the case. However, meter show can be repositioned so the meter hangs over it's left (by default it hangs over it's right) so it should be fine.