Is there a basic wiring diagram example for KVM (including USB devices)?

Generally the keyboard and mouse should go into the HID ports of the KVM. However, not all devices may be compatible (see the FAQ [Official] L1Techs KVM FAQ -- Ultimate Guide & Help!). Not sure about the pass-through on the keyboard, but I believe that should go into one of the USB 3.0 ports of the KVM (i.e. not the HID ports).

Why do you think you’d need USB A to USB A cables?