Can you independently set desktop wallpapers on the two screens? I know this seems nitpicky but it's literally impossible with Ubuntu/Gnome as far as I know; I have one vertical and one horizontal and have to just go with a solid color background to make that work.

Yes. It was actually more tedious to do the inverse when I wanted three screens to do a rotating wallpapers from the same set of folders as I had to set the list of folders three times