Hello, I apologize for bringing up such an old topic, but I also became interested in this question and decided that the best solution would be to continue this thread rather than create a new one.
I think that the choice of Systemd was clearly not a joyful one, but rather a forced one.
I remember when I had to write a lot of bash scripts. I think there were similar problems with the development of Qubes.
Fedora-based dom0 plays a huge role, since all Qubes tools are sharpened for it, but I don’t understand why the choice did not fall on debian or even something from * BSD, for example hardenedbsd.
Perhaps this is also due to the fact that the development of Qubes began a very long time ago, and at that time much was not known about Fedora and systemd, and it was difficult to imagine the vector of their development.
Interesting branch, I do not understand why it is idle.