...and of course, there's Erica's MScale module. The problem is that the Moogs can and do use negative CVs for pitch. There's ways to get around that that don't involve an extra module, but they can also be a PITA.

Even with the Matriarch being used for modulation signals, you're going to come up short in terms of capabilities. Fact is, a far better way to judge if a build is going to work would be simple math: your "voicing" modules (VCO, VCF, etc) should only be about 1/3rd of the build, while the other 2/3rds-ish are your "supporting" modules. As for the...uh...whatever is going on with those 4ms Listens, allow me to hip you to THIS: https://www.modulargrid.net/e/emw-8-channel-stereo-mixer Yep...eight stereo-ins, takes up far less space. And there's a hint there...

If you rework things here so that you have more functional density in your modules...without compromising the ergonomics, natch...you'll find more space opening up, just as with this one module. And the price will come WAY down as well.