Why not just log in as the user in TTY and then start it?
I’n not sure I understand the use-case of why it needs a Plasma session to start a script that needs to keep running afterwards. If the script itself does not need a plasma session, then you can just start it as a user service with systemd.
I opted for the version with RAM and nvme for $270. had to pay shipping, but no import tax (lucky me). So all in all it was about $300 for me.
And yes I run Linux on it. Arch Linux to be precise. Have not encountered any driver issues.