I used to have a chaotic evil setup. I was writing code for some AIO PCs used as kiosks on the shop floor, so I needed to test the code on one of the devices. At the height of things, as we were transitioning to a new system, I had two of the kiosks (running different OSs), my laptop screen, and two external monitors, all of them running software that let my mouse and keyboard treat them as one computer.