Comment 4 for bug 1875125

After grokking the gnome documentation and poking around the filesystem some more, there appears to be an undocumented way to disable the desktop-icons extension to fix the workaround.

In /usr/share/gnome-shell/modes/ there is a json file ubuntu.json. It has a list of enabled extensions one of which is the desktop-icons extension. It looks like this:

{
    "parentMode": "user",
    "stylesheetName": "Yaru/gnome-shell.css",
    "themeResourceName": "theme/Yaru/gnome-shell-theme.gresource",
    "debugFlags": ["backtrace-crashes-all"],
    "enabledExtensions": ["<email address hidden>", "<email address hidden>", "desktop-icons@csoriano"]
}

Editing ubuntu.json and removing the entry and extra comma for desktop-icons allows nemo to provide desktop icons and drag/drop functionality that was previously non-functional.