What further steps do I have to do to properly re-install, than overwriting the old files with the new ones?
Are you suggesting I should just nuke the LXC and do the whole setup again?

Hello again Factorio Forum,
a few days have passed, and I still could not get the upgrade to work. Luckily I still had a backup of the LXC before the update, which I've rolled back to, and tried updating again.

This time I changed the rsync command to a simple cp -r, and logged the verbose output ...

Hello Factorio Forums,
I have trouble upgrading my headless server to 2.0.73. The last two stable upgrades worked like a charm, no problems there.
The server is running Debian 12, kernel 6.17.4.

To update the server, located at /opt/factorio , I performed the following steps:

mkdir /opt/tmp
wget ...

+1

I haven't seen an impact on UPS yet (1 Space Platform orbiting nauvis), but I fear that with more platforms dropping something from orbit every other second might use resources that could go elsewhere :)