Well I am running Ubuntu 20.04 and have experienced boot issues after update multiple times. Currently my laptop is not directly bootable as zpools are imported in wrong order / not imported at all so I have to import them manually. As there is not enough information how the freaking boot works and I am not prepared to study grub2 to figure it out and I am in this situation for 6 months.

This is my last root ZFS install on linux.

I had problems with fedora before (where at least ZFS wasnt supported and I was expecting problems), I am having problems with Ubuntu now and I never had any issues with zfs root on FreeBSD in ~15 years.

I am sick of distributions "moving fast and breaking things" on my back.