Ubuntu 18.04 single Xorg screen config with internal intel graphics and nvidia eGPU

Hello. I have a Thinkpad T480 with integrated Intel GPU and Nvidia MX150 and have recently got the Lenovo TB3 Graphics Dock. The Graphics Dock has an integrated Geforce 1050.

I had this system set up with the experimental 435 driver with Prime Offloading and working nicely with an external monitor connected to the laptop’s DP port, which is wired to the internal Intel GPU. With the new dock connected I’ve amended my xorg config for the Geforce 1050 and connected an external monitor to it. I am trying to maintain the same setup (prime offloading via the nvidia GPUs) while displaying the X session with the Intel HD card and running a dual display setup - one internal laptop display wired via the Intel HD card and one via the external GPU HDMI port.

I am not entirely sure if this is even possible and my xorg understanding is rather rudimentary, but I’m posting bellow all the relevant config and outputs:

xorg.conf: https://pastebin.com/zdJhNj8c
Xorg.0.log: https://pastebin.com/rgBxnHtw
Some xrandr command output: https://pastebin.com/qMqgaV5D
nvidia-xconfig --query-gpu-info: https://pastebin.com/ZVmw70Ba

My assumption here is that for some reason the xorg configuration is amiss and xrandr does not see any of the outputs on the nvidia card, hence xrandr --list providers has

Provider 1: id: 0x311 cap: 0x0 crtcs: 0 outputs: 0 associated providers: 0 name:NVIDIA-G1

for the NVidia card, but I have no idea how to proceed or if what I am trying to do is even possible. Please assist!


EDIT: So to actually specify the problem - nothing is displayed on my external monitor and xrandr does not see it, even though nvidia-settings does list it and I can see that it is being probed by xorg in the log.

Not possible.
Using exernal monitors connected to the nvidia gpu requires to use the standard ubuntu prime output which renders everything on nvidia.

This is because the current NVidia driver does not support Sink Output, correct? Is that planned? Any ETA?

Correct. Planned? IDK, probably. ETA? no.