Oh, absolutely. They’re fastened together with flush hex-head screws- Once they’re tightened there’s no give whatsoever. Allen keys were also provided with the add-on kits for vertical standing and for joining the cases, and it wouldn’t be difficult to separate them.
As a test I did actually just lift the system (and with one hand!) from just the top option. Apart from the weight being awkward it was all good.
I really do think that these cases are gonna take off, and I hope they do; I used to work at the print shop where Dan, who runs Tall Dog, got his materials made and I recall him very enthusiastically mentioning a project like this to help beginners have something scalable and affordable to start with. Had these been out at the top of the year when I got into euro, it would have been an easy choice between the unpowered Moog cases and the non-expandable Make Noise skiff.