Ubuntu 18.04 LTS includes X and Gnome now, so I'm sure DisplayLink intends to support it, instead of Kubuntu. Logging in works fine, and there's no mouse flickering.
Here's a link to the output of the support tool:
https://drive.google.com/file/d/1Q6R...ew?usp=sharing
Why are the monitors only showing 640x480 in "Displays" and xrandr?
Thanks!