May be you can do this with Virtue. You would put a virtual desktop on each screen, and Virtue allows you to move windows between desktops using any key combination you want.

I've used dual monitors for years: How I finally fixed the 'invisible wall' ...

If you have a multi-monitor setup with different monitors running in various orientations, your mouse is supposed to adjust to the current orientation of the monitor. However, we have noticed that in ...