I would be interested as well. I am looking for a dock to support external monitor 2560 x 1440 at 60 Hz, bluetooth keyboard/mouse and audio via USB as well.
Ethernet port would be an advantage, however it seems to be a problem at the moment.
Could you please confirm that you have all these running on WD15? I got 9360 XPS with Ubuntu 16.04 just a few days back.