Interesting design ideas! A few might work for cruisers, especially if you're at the dock in a city with bike paths.
When we cruised the coast to the Bahamas and back, we got a lot of use out of a couple of the smaller Dahons.
So we bought a couple of folding bikes a few years ago with bigger wheels (20" as opposed to 16").
As it turns out, most of our cruising area, coastal Maine and New England, isn't that well suited. And locally, much of the land we visit are islands. You'd think they would be perfect but island roads are narrow, often no shoulder, so it's a little dicey.
We love to bike and do quite a bit where we live (endless bike paths), on full sized bikes of course.
2, 20" folding bikes take quite a bit of space. If you have the space, get the biggest wheel that you can store.