Thanks for the advice. I was looking for powered cases today and had some sticker shock, so I think you're right about keeping the Neutron in it's stock case.
Erica Synths has a drum mixer with compression that caught my eye.
https://www.modulargrid.net/e/erica-synths-drum-stereo-mixer
I might not want to mix entirely in the DAW after all.
Expert Sleepers has me scratching my head. It looks like they are using ADAT lightpipe as a way to multiplex several signals onto one cable, but I haven't figured that out yet. They have some non-Linux software, Silent Way, but I think it isn't necessary for most use cases?