Just passing this discovery along fwiw, perhaps some KDE users might be
interested . . .
I've used KDE's virtual desktops feature for a long time, but it was
always a small annoyance to have to share the same wallpaper across all
desktops. So I've been using the "wallpaper switcher" applet which
associates each virtual desktop with its own wallpaper, and it worked
well. Unfortunately, it breaks with the current Plasma and so I lost
it with the 15.2 upgrade.
However, the author of wallpaper switcher recommends using "vallpaper"
(that's a "v"), which not only provides the same multiple wallpaper
functionality, but adds some bells and whistles, too. Installation is
very simple, and it integrates nicely (as a "plugin") with the KDE
Desktop Configuration. IMO definitely worth a try if you want a
different wallpaper for each virtual desktop.