please read my entire post, especially that part:
i'm not writing about block level backup.
my approach is a highly optimized process for system restore, as hardware independent as possible.
i'm talking about the script https://pve.proxmox.com/wiki/Automated_Installation#First_Boot_Hook_Section
which technically of course could be ran manually after install.
i backup /etc and some other folders daily during runtime. restore during...
I've built a first boot hook script for one of my hosts, which restores nearly everything from a zfs pool inside the host. the hardest part is to keep the script up2date when you make changes on the host...