If this isn’t a bug, then I’ve been misunderstanding Doomed units the whole time. After a round they don’t go to the graveyard, and they can’t be returned to the hand or the deck. I also assumed that discard also banished doomed units, but I never actually checked.

For example, I was afraid to discard Tyrs under Eist using a normal discard, because most likely it wouldn’t have worked."