Both of the solutions (Patchbox-OS & Pi-top Complete) appear to be outstanding in design and engineering.
I asked one of the pi-top reps if you could run a dual-boot OS on the same SD-card… it turns out it isn’t possible.
To run multiple OS’s on one device, you must install each OS on it’s own separate card.
Good luck with your installation work… let us know how everything ultimately transpires.