My adaptor (link in #3) is working mostly fine in Arch Linux, but it needs some configuration.
Sometimes it gets broken with kernel updates.
As I mentioned in Arch Linux Wiki, I have written a switch service for DisplayLink, which helps you to easily switch between displaylink and optimus. It seems that it is not needed anymore in Arch Linux, but you could try it for ubuntu, if you find it usefull. Here is direct link:
https://github.com/Ashark/DisplayLink-switch