I have just pushed an update to my
desktoppr tool which can change the desktop on macOS. No new features but the installer pkg is now notarized.
And because you need to use a newer Xcode and Swift 5 to notarize the tool, it now requires the Swift 5 Runtime support for command line tools when you install it on versions of macOS older than 10.14.4. (On those older versions, you can also continue to use desktoppr-0.1)