[dataworm]

I'm not sure about this mode requiring special Apple firmware, but it definitely does not use 6 lanes of HBR3: https://forums.macrumors.com/threads/caldigit-introduces-usb....

I don't think Thunderbolt ever uses anything other than 4 lanes per DP connection if the GPU doesn't limit the lane count, because Thunderbolt deserializes DP packets, transmits them over the link and serializes them back on the other end, so it can't negotiate the lane count on the host side.