Hi!
I'm using Tinkerboard S R2.0 in headless mode, but with LightDM (kiosk mode). It's connected to HDMI display, and I soldered display's backlight on/off contact to a relay that can turn on/off the backlight.
I see that Amrbian turns off image output (launches screensaver as a black screen) after 10-15 min, but I could not find out where those settings are stored. Please help to find out.