To get an idea about how things would work in practice, I suggest printing out the layout as close to 1:1 as you can get it, and play around with it a bit.
If you feel fancy, you can glue it onto some cardboard, make holes for the potentiometer shafts and plugs, and mount some pots/knobs on it. That’ll give you a much better idea about how much space you prefer (I mean, you are building for yourself after all).