Is there a way to start plasma so that, after running startplasma-wayland, the Desktop is locked and that a password has to be entered before interacting with the desktop? I see that there is a DESKTOP_LOCKED variable referenced in startplasma.cpp but it looks like this functionality isn’t wired in on wayland for non-systemd starts. Is there another way to do this on Wayland. Or should I file a bug report/feature request for this?
Is this meant to be an effect of running startplasma-wayland, or could you run another command after it? Something like using loginctl would work to automatically lock a session, but I don’t know of anything built-in to plasma to do this, maybe there’s an “autorun a command on an event” feature, or an autostart flag that starts when the desktop is loaded?
Systemd offers a very nice and easily managed way to set session environment variables by just put environment files in the ~/.config/environment.d folder. If you are launching from SDDM, you can add environment variables to ~/.profile or ~/.bash_profile, which would also work fine for most other ways to start Plasma.