So, the consensus would be at least something of a mallard based domestic hybrid. Even Co-Pilot thinks that. My neighbor has had domestics (the big all-white ones) in the past that visited my place, maybe one or two of them found a mate even though I've never noticed odd ducklings.
The differences between these two and the domestics that have visited in the past is that these are much more normal sized, the domestics were always about 20% bigger, and they were bullies to the wild ducks in that the wild ducks would always leave to avoid interacting with them. This pair is near normal sized for wild mallards, and their behavior is much more like the wild ducks, although the other mallards tend to give them space.
Anyway, cool but kind of goofy pair to have around this year.
And no, I've seen no sign of these two having offspring.