Sure, I was just curious, since you mentioned not wanting to use ZFS without kernel support and BTRFS does have that. Being familiar with ZFS, I guess is a decent explanation.
When the topic of backups came up last year, I talked about my current solution: https://news.ycombinator.com/item?id=41042790. Someone suggested a workaround in the form of zfsbootmenu but I decided to stick to the simple way of doing things.
[0] https://borgbackup.readthedocs.io/en/stable/index.html