Yes I am thinking of using my little TV (composite AV input only (from an HDMI-to-composite dongle)) as my second display. Going command line-only would be ok if I don’t have a choice, but then I watch miniDV and VCD footages sometimes. My Mint machine was broken so i didn’t have a chance to test that. So not sure if it could go lower than VGA or if I am asking the right question.
The dsektop environment really doesn’t have anything to do with it. That’s up to the video drivers and display server, be it X11 or Wayland. I haven’t any idea which desktop might offer you the best tools for configuring those things though. Just as a rough guess, I’d guess KDE Plasma, perhaps XFCE?
Xfce is probably the simplest option. It can do most anything without much effort. I’d suspect with a little effort you could do it.
