Along those lines
If you carefully work everything out ahead of time you should not have to route any wire or plumbing behind the upholstery and almost everything of this sort can be hidden. I did design my own "stair step" center console in our RV-6A that comes up between the side by side occupants that facilitates this (as well as 4 fuel filters, 2 fuel valves, aux fuel pump, primer solenoid, primer switch, aux pump switch and manual pitch trim control). All of the wires and coax cables that go aft from the instrument panel enter the top through ribbed flexible conduit then go aft through the the center of the spar web and into the corners of the pitch control push rod tunnel for distribution to the lights, servos, antennas, fuel tanks, pitot heat, ELT, and strobe control box. I routed the static line under the upper left longeron. It is a part of the build process that pays off later if you give this a lot of thought and work. It is a little surprising how much the upholstery does for the appearance and sound proofing.
Bob Axsom