I am curious as to exactly what USB Type-C alternate modes (and variations of those modes) are supported on the 15" 2016 MacBook Pro and later. I've done some searching on the Internet, but I've been unable to find any credible source of information on the subject. I would consider a credible source of information to be:
Official Apple technical documentation explicitly describing all supported USB Type-C alternate modes which are supported on the device. (All I've found so far is marketing info, which isn't specific enough.)
Analysis of USB PD traffic which might indicate supported alternate modes and capabilities.
Some sort of command-line utility or tool which is able to dump this information.
I already know that the USB Type-C ports on this machine support the following alternate mode configurations:
4 lanes using Thunderbolt 3.0.
4 lanes using DisplayPort 1.2.
2 lanes using DisplayPort 1.2 and 2 lanes using USB 3.1.
But I'm pretty sure it supports additional variations.