I have an old Belkin USB 2.0 switch from god-knows when that works beautifully. I use it to share a hub with a keyboard and mouse attached. I’ve given up trying to find a 4K60 x2 DisplayPort KVM that doesn’t suck.
>>bombit+tf
Seconding a recommendation for Startech's KVMs. They have an excellent USB stack which handles complex USB hierarchies flawlessly -- I've successfully used mine with chained hubs, weird HID devices like Apple keyboards, and non-HID devices like disks, audio interfaces, and even stranger things.
>>stamps+g9
I couldn't find the details on their site, but do you know whether the 3.5mm audio jack is 3 or 4 pole? I've found that most KVMs have the 3 pole jack, meaning it just supports audio out, but I need 4-pole so my headset microphone works.