2021-07-26, 19:55
Leaving this here for time travelers from the future finding this thread. I executed getedid create and after a reboot, everything works beautifully. Even when the TV is in standby mode my chromebox sees it as active and I can set resolutions from a script. I got initially sidetracked by the long explanation here https://wiki.libreelec.tv/configuration/edid thinking I needed to issue multiple commands, but the getedid script does everything automatically on a chromebox.