Here are some descriptions of what others have been up to with their Dx0Q.
In November 2020 I heard from Simon who had set his Dx0Q up as a MythTV front end. Originally he had been using a Shuttle XPC for this job.
* COW - Copy On Write.I am currently running a MythTV front end on a Dell DX0Q Thin Client - AMD GX-415GA 1.5GHz, 4GB RAM, 32GB SSD - bought a few weeks ago from eBay for GBP 30.
The software setup is Debian 10 XFCE desktop plus the repository from deb-multimedia.org (for the myth client), with redirection of temp/log files to tempfs and use of dracut to build the initramfs so that the root FS can be loaded read-only with a COW[*] layer on top. Other than the (probably unnecessary) diversion of the OS writes to tempfs/RAM it is a standard setup and runs fine as a MythTV client across a wired network, playing 480p video content. I am driving the TV in the bedroom with it.
It runs cool and silent. It replaced a Shuttle XPC with an AGP (!) video card which was neither cool nor silent.