I am running Deskscapes 10. With the setting to pause deskscapes on maximised application - only pause monitors that match the above rule. It doesn't seem to work. If I maximise a window on monitor 1, it pauses monitor 2, but won't pause monitor 2 when an application is maximised on monitor 2. Monitor 1 is in landscape, and monitor 2 in portrait mode. Each  monitor is set to run a different video, since Deskscapes can't rotate videos to accommodate portrait monitors. If that feature was added in, and I could run a single video across both monitors, automatically transformed to suit the geometry of the monitor, I suspect that might make it all run a bit better, and probably use less cpu/gpu too, rather than rendering 2 versions of the video simultaneously. 
Both monitors are currently running off an RTX 3070 in 4k resolution.