@Juankprada True, it require compatible ratio/resolution. I remember I succeed with xrandr on X11 to map a 1440p monitor on a 1080p Cintiq 13HD with downscaling. It was a fun test, but the fonts were small and blury, and setup wasn't that stable, many small glitch to clone with a scaling like that... I was probably in a territory of 'the feature exists, but nobody ever beta-tested it in production so it was bit rotten'.