Yeah I'm hoping they could add it as a feature, more and more people going with ultrawide and out of my 100 or so deskscapes, only about 7 or 8 still looked good in 3840x1200 resolution. (I have many from you, I love your great nature deskscapes).
I tried a 'fake' dual desktop using DisplayFusion, but that didn't fool DeskScapes unfortunately. Not only would it be nice to have two options, it makes DeskScapes viable again. I wouldn't have paid for DeskScapes if I originally had the long monitor, because you either end up with really stretched out scapes, or you end up with giant 'blank' spaces if you do centered (to make it look good/unstretched), but at that point you'd just go out and get 3840x resolution hd static image and no longer use DeskScapes.
I know it'd be DIFFICULT to program in dual desktops or trying to fake it. But it wouldn't be difficult (I would believe) to choose two and have them run horizontal to each other as a single 'stitched' deskscape. You might also want to add vertical stitched option while at it, for people with large vertical 2nd monitor.
I really think it'd open up a big market for DeskScapes for the ultrawide monitor users.