It would be nice to be able to use xscreensaver as a replacement for the default GNOME screen lock. With the move to sddm (see FL-7907), this actually becomes easier.

I have some work in progress on implementing a dbus-based method for xscreensaver to be locked via the default org.gnome.screensaver lock mechanism. This would allow xscreensaver to be a true GNOME screen lock replacement and would be a nice option to have.