Finally works flawless so far, just like it did with High Sierra 10.13.3. nearly a year ago. Plus a working clamshell mode! Yay!
I keep my fingers crossed that the forgotten HDCP video support will eventually also come to macOS.
MacBook 12-inch Early 2016
Mojave 10.14.2
DL Driver 5.0.1
HP Elite USB-C-Docking Station G2