Hi Ondrej,
I think it would be best if someone has finished the upstream systemd support. I am currently busy with other more important stuff, but if there was a working MR I would be happy to do the review and also do the backport to 9.18. The change is isolated, so it won't create any fuzz.
The code has been merged in 9.19.6. Do you think we could backport it, either upstream in the next release or in 9.18.8 for Debian?
I'll look at enabling this in the experimental branch. Bernhard