Hi! After installing Ubuntu Budgie 20.10 the following issue: When the machine is locked and the monitor turned itself of and I then remove the external monitor, the computer wakes up unlocked. I guess this is not a feature but a bug.
Sounds like an issue. Would need someone to dig into the gnome-screensaver code.
I would though say, screensavers are not security enforcing tools. Anything about the X windowing system is easily subverted by anyone on a network.