I have never used displayport but have used USB docking stations from (Amazon) Targus and MediaSonic to run two monitors (HDMI & DVI/VGA) and a third from the notebook HDMI socket. Key to docking stations is whether it is true dual display vs display mirroring and the number of USB 3 vs USB 2 sockets. The other discriminator is the power available from the power supply (usually between 20 and 30 watts).
Once you look at the ports, you can generally identify the core, suspect all use the DisplayLink engine & is mostly badge engineering and physical layout.
