It does not work even if you created the family and you want to re-export that zoi later.
I had created this temporary zoi when building my mansion.
He got tangled up with another of my favorite zoi and they made a family.
I wanted to save him as a permanent addition to my zoi collection.
Even with CustomZoi, when I try to save him it give bogus reasons like needed ambition, name and other crap. (He has all those things !)
I reported it here :