I have an ER-301, and can record CV there, and also manipulate it in time and frequency domains. Even slice it.
So why Max? Because I had the idea that it would be interesting if CV recorded in Max could be represented as a spline curve, with handles that could be used for editing. It would be nice to be able to do all the things you can normally do to automation curves in a DAW.
I don't know enough about Max to know how hard this idea would be to implement. Any particular objects/patchers I should take a look at?