Well, if you want to go with open rack frames, I think there's a housing solution here that you'll dig (provided you're in the USA). I ran across a firm out of Missouri that builds serious, solid portable racks with a very shallow footprint, and I now have several pieces from them. Check this out: https://prospeakerparts.com/collections/rack-cases-carpet-covered-2f/products/procraft-10u-12-deep-equipment-rack-10-space-made-in-the-usa-w-rack-screws This could also hold a power conditioner or a tile row at 10U, but if you only want the space for 9U worth of frames, they've got that too: https://prospeakerparts.com/collections/rack-cases-carpet-covered-2f/products/procraft-9u-12-deep-equipment-rack-9-space-made-in-the-usa-with-rack-screws And there's several others that they do that are fairly Eurorack-friendly, including some snazzy angled racks for studio use.
But the back's open! Ahhh, that's easy too. They carry unmounted rack rails and both solid and vented rack panels, too! You could even go as far as mounting a 7U panel on the backside of that 10U unit and then a Eurorack frame in the bottom 3U for mounting power inputs and supplies, or even a dedicated 1/4" output pair...then just slap some blanks on the rest, and there you go! And that 12" depth is super-easy to tote, but if you go with a smaller cab, you can get into 9" depths: https://prospeakerparts.com/collections/rack-cases-carpet-covered-2f/products/procraft-6u-9-deep-equipment-rack-6-space-made-in-the-usa-with-rack-screws And in fact, there's one sitting to my immediate left right now, housing the remaining patchbays on the right side of the desk. Nice stuff!