

There are KVM switches that allow something closer to that at least, but usually only for 2 hosts (pcs). It stands for “keyboard, video, mouse” and they originated in the server space, but recently became common in the home/office as well.
They main purpose is to switch use of the monitors and any attached input devices between PCs. But there are models that allow mixed/shared use as well. If you’re looking for one that supports 3 monitors and 3 hosts, with some splitting options, that might be harder to find or cost as rather pretty premium (hundreds).



The arch package has to be built somehow. You could look at that packages source and/or content to figure out how to manually do it on your system, or wait/hope the deb is being maintained and gets fixed.
It’s likely mostly some plumbing, like a systemd service with it’s configuration, to get the audio routed properly.