I've noticed that, when setting up wallpaper on multiple monitors that are not all of the same size, DF assumes that resolution to display size ratio is the same for all of the monitors.

This creates issues when setting up wallpapers (and potentialy some other settings).

In my specific case (4K-2K-4K, all 27"), I had to set the horizontal offsets on left and right monitor to +/-640 respectively ((3840-2560)/2), as well as scale the image on the middle monitor to 66.67% (2K to 4K ratio is 2:3) in order for it to look normal on my setup.

It would be really nice if we could tell DF sizes of our monitors so it can do this math automatically.