I really wanted this story to be true, that we would be able to have this level of hard evidence, but I highly doubt it.

Remember the states with misprinted ballots a month ago? They blamed the private printers they used and reprinted. They did not blame DHS.

Even if they provided the ballots, the states know how many went out and how many were returned. They can still return legal ballots illegally filled out and the watermark would do nothing.