Comment 6 for bug 1987190

... and, answering my own questions:

- both the pre-fix and the post-fix datasets are mountable on a 20.04 zfs-0.8.3 pool (zfs recv'd from an affected 22.04);

- after a mount/unmount, the MAC is fixed, and we have no need for the patched zfs module anymore.

Cheers,
Walter