Just to clarify what you said, Alternate Mode allows two directly connected devices to negotiate what the SS lanes and a few other wires are used for. The signa

Just to clarify what you said, Alternate Mode allows two directly connected devices to negotiate what the SS lanes and a few other wires are used for. The signaling that happens over the wires after negotiation is totally outside of the USB spec as the signals are simply MUXed onto the wires. In theory you could MUX anything over the wires as long as the signaling parameter fell within the specs defines for the cabling.