Illumos is the repo of record. Everyone of the above OS distributions feeds changes upstream keeping zfs in sync between platforms. No one relying on zfs wants

Illumos is the repo of record. Everyone of the above OS distributions feeds changes upstream keeping zfs in sync between platforms. No one relying on zfs wants forks or incompatibilities. That's one of zfs main selling points, that you can yank a pool from FreeBSD and shove them into illumos and vice Versa.