This does not surprise me at all. I have a 4k screen and just thinking about all the fiddly bits between HDMI, HDCP and Freesync/Gsync between the computer and

This does not surprise me at all. I have a 4k screen and just thinking about all the fiddly bits between HDMI, HDCP and Freesync/Gsync between the computer and the screen makes it quite difficult to build a switch. VGA was primitive, but simple to switch, those times are gone. My computers usually make a fuss if I just switch off the screen and back on, because both sides seem to have some active signaling going on and way too much logic. Ps: USB switches for the KM parts are rather simple though and there is a healthy offering (+ you can build this yourself with some extension cords and a simple USB switch). Also, more and more of my devices move wireless (e.g. audio).