RE: XPS 13 9343 and 9350 QHD+ No Display Issues on Linux
Yes I installed the card myself. Dell doesn't offer it as an option. I was very easy to install.
Here is a link to my notes on installing ubuntu 15.10 on a new Dell XPS 13 9350.
It seems to be running pretty well right now, but there are still a few small issues I'm trying to tackle, like the touchpad and encrypted swap. I'll be updating that document as I go along.