Hi Bret,
Interesting idea indeed 
It sounds like it has some similarities to my CvPad module.
CvPad is probably too big for what you need, but it performs quite well. Perhaps I should make a smaller version of it without all the features, and just a single CV output. Here’s a quick sketch:
I’m not into modular very much these days, but I’ll think about your idea!
Cheers,
Marc