I built the Luggable PC for me, but I recognize the trade-offs would not work for everybody. [Tux Lab] proposed something easier to build and modify, with the trade-off of increased size and weight. The discussion resulted in this: a luggable frame that integrates a VESA monitor mount and a tray to hold a small form factor chassis.
Construction of the initial prototype is documented at this link.
If this project gains traction, I'll create a separate Hackaday.io project page.