Earlier quoted context omitted.
There was an early SMR talk by a WD (IIRC) engineer to a crowd of ZFS devs and sysadmins, and the engineer thought it should fit well because he misheard the default record size being 128MB rather than the actual 128kB, so thought it one record would fit one zone.
That seems like a pretty big mistake, are you sure that's real? ZFS has a lot of genuine potential to work well with SMR drives, but that potential depends on glue code that nobody has written yet. I think BTRFS is halfway there?
The problem is that you cannot buy host managed zoned disks.