Assuming Thunderbolt 3 to the docking station and either Thunderbolt 3 or DisplayPort (1.2 or higher) to the display, does G-Sync pass through a docking station, or does the intermediary hardware prevent G-Sync from working?
No, it doesn't work. I tried this with my Alienware 13r3, ACER Predator XB241H and a CalDigit TS3 Lite. 144hz 1080p is no problem, but it's impossible to get GSync to work through the Dock.
GSync works with DP-Port on the Laptop itself, but I have to use 3 cables, wich is a bummer :-(
I am using a Msi Vortex G25 and a 240w Dock from Dell. And I would say the answer is: it depends. I tried to use the DP port and the mini DP on the dock but it won't work. However, I recently bought a new USB-C to DisplayPort cable and connected is to the dock. BOOM! G-sync notification pop up from the corn of my screen.