No existing way of managing extensions
There is no existing way of enabling/disabling nautilus' extensions.
Example 1: i installed KDE Connect and the "MConnect" GS extension, which comes with a nautilus extension (via the python binding). Later i uninstalled KDE Connect, disabled the GNOME Shell extension, but the nautilus extension still exists and try to establish dbus connections. I have to search for it in ~/.local/share and delete the script if i don't want polluted logs
Example 2: i don't care about the "sent to" extension, and i would have to delete files in /usr/share, or to remove packages (breaking dependencies) if i want to get rid of it.
Example 3: i have Tilix, and the extension "open in Tilix", so i don't care about "open in a terminal", but can't remove it.
The user should be able to disable/enable extensions instead of deleting them. This could be integrated in the Preferences window, or at least just in a gsettings key.
Benefits of the solution
Giving to the user a better control over what additional actions are polluting his contextual menus, without requiring the removal of obscure packages or the deletion of files the user shouldn't even know about.
A gsettings key for activated extensions, if not exposed in the Preferences window, implies that the user have to dig in the dconf editor in order to use what he installed, or that all concerned packages have to be updated.
If exposed in the Preferences window, it means more preferences, and i know you don't like that.