RE: Looking for WD15 Firmware Update
Fully up-to-date firmware/bios on 9350, 9360, and WD15 (180W). Updating the WD15 was a pain because it required windows.
I don't put my laptops to sleep while connected to the WD15, and I've not tried to use the audio.
As long as I disable autosuspend on the realtek ethernet device (USB_BLACKLIST="0bda:8153" in /etc/default/tlp), I have no issues with the wired networking.
My external display is 2560x1440@60hz and works well via HDMI.
Things have been working well since the kernels 4.9 or later...