Change background of specific display

[RubikOwl]

Maybe I'm going crazy, but I feel like in an older version there was an option to change the background of a specific display. Even if it wasn't though, I'd love to see this feature as I work with enough random screens that being able to change it or set a default for new screens that connect through this tool would be super useful. Not sure if it's possible, but it could be a nice addition for those in A/V.