That is pretty cool. Oddly enough something I've been thinking about would be a high dpi "ribbon" screen, something that is perhaps 14 - 16" wide by 3 - 4" tall. To sit just behind my nice mechanical keyboard. That screen would have application specific tool bars with large icons and easy to tweak controls (sliders, buttons, etc). That would allow me to give over my "big" display to the project workspace, whether it was a circuit, MCAD design, or illustration. The "special sauce" being that I could render to it as a screen and it would have multi-touch capable gestures for the controls.
I prototyped some of that with a mimo 10" touchscreen[1] but in my vision touching a control on the 'ribbon' screen doesn't steal the mouse pointer :-). I've been playing lately with some ST Micro 32 bit parts that can drive a display and use BT LE to communicate back to the PC. It may be possible to "download" control panels to the screen and then get the feedback through a BTLE handler rather than trying so somehow hook the event handler of a standard App and have it take control selection events from this screen/non-screen entity.
So if you find a long and narrow high DPI screen, DVI, MPI, or even VGA driven would be ok. And a capacitive touch layer, I'd love to get one of those to play with.
[1] https://www.mimomonitors.com/collections/10-inch-monitors