1. Download he official ubuntu package from

http://www.displaylink.com/downloads/ubuntu.php

./displaylink-driver-1.4.210.run --target .
tar -xzvf evdi-1.4.210-src.tar.gz 
make
sudo cp evdi.ko /lib/modules/4.14.1-gentoo-blackmagic/kernel/drivers/gpu/drm/evdi/evdi.ko
depmod -a
cp -r x64-ubuntu-1604/* /opt/displaylink/

It is outdated, but some of the files can be used.

DisplayLink Overlay

Run D3100.sh