Change Gnome 3 wallpaper without animation or flicker

Approx 10 years ago I wrote a small program to give me a simple "animated wallpaper", which worked well on whichever versions of Fedora and Gnome were current at the time (I believe it was Gnome 2). Recently I came across it again in my archives and am trying to get it to work again with Fedora 28 and Gnome 3.28.1, but have some small issues. The program wrote a new wallpaper file to disk once a second, and then set it using a system call to gconftool-2. This low frame rate was fine since the difference between two successive wallpaper images was too slight to be noticeable. I see that nowadays I need to use gsettings instead of gconftool-2. This works fine in that the wallpaper changes correctly, but there is an animation effect every time it's called, which obviously becomes annoying if it happens once a second. I've discovered I can disable these effects with gsettings set org.gnome.desktop.interface enable-animations false but the background still goes momentarily black each time I change the wallpaper, giving a flickering effect. So my question is: How can I get the wallpaper to change instantly, with no animation or flicker? I've seen that I already have an animated wallpaper pre-installed with Gnome that uses an XML file to specify the time a new image should be shown, and the duration to transition between images. If this is the only/best option, I can try to adapt my old program to use this system. But this would probably involve me writing thousands of images to disk, and then I'd have to write the XML. If there's a simple change that would allow me to avoid this, I'd love to hear it.