I think I can safely say Surface Dock works. I use my Surface Book 2 mainly as workstation and in my office I have the dock and never had any issues with external monitor.
Tried working from home and got the flickering issue using the USB-C to HDMI connector. However the external monitor is different at home so could be related to that, but my Surface Pro 4 don't have any issue when using mini display port and the same external monitor.