I start my window manager with systemd service units (following this tutorial). After I log in at tty1 the following gets executed in .zlogin (I'm using ZSH as a login shell): if [[ -z "$DISPLAY" ...
So all power management settings are disabled. And we don't get the login prompt when the tv stays on for a long time. The comp does not go to standby. We even disabled 'show login after screensaver' ...