Hi everyone,
I know that no one has time to do an audit on the code, but I've uninstalled light-locker with XFCE (Debian/testing) on my laptop (Dell Latitude 5X90) because it was nearly unusable. I couldn't get my session back because of VT switch. I installed xfce4-screensaver and it was just working. The desktop isn't shown when locking, and I've never experienced such an issue with my personal desktop computer, using Debian/unstable, installed since more than 2 years.
I think this is an alternative that could work better than light-locker for some users.
Have a nice day,
Adrien