I'm told that Tesla were part of the CCS group but walked away when it was clear they weren't going to get what they wanted. My understanding (though sadly I have never found any concrete technical specs or measurements etc to confirm or deny this) is that the Tesla conector is not DC-Mid. DC-Mid is an unmodified Type 2 connector with the 4 phase+neutral pins used instead as a pair of + and a pair of - connectors, with current limit of 70A on each pin (i.e. not much different to the 63A limit for AC charging). Tesla have said repeatedly that their connectors are not made by Mennekes, that they are “more robust” and that a normal Mennekes connector could not cope with the power of supercharging. There's a video somewhere of Elon saying standard connectors would melt if they put 120kW through them. Supercharging runs up to about 340A, i.e. 170A per pin though admittedly only for about 15 minutes continuously. Rumours abound that the pins are deeper or fatter or bathed in unicorn tears or something. The signaling on the Tesla connector is CAN.