(feature request) Command-line option for custom .desktop directory

On Debian, I never use /usr/share/applications and I always use my custom launchers/scripts from a directory of mine. It would be nice to call xfce4-appfinder --desktop-directories ... to pass a custom directory or list of directories.

Adding them to the systemwide applications directory would mess with the autocompletion. A couple keystrokes currently matches only one launcher. This is fast and efficient, because I run the launcher a lot of times. But the systemwide directory has so many entries (useless to me) that more typing would be necessary to match the correct launcher.