[rbanffy]

> unlike votes by mail where you have identification (we simply can't have here, for instance)

We could, but it'd need two envelopes, one that identifies the voter, and a second, without voter identification, with the vote itself. A first election official would validate that the outer package contains a vote from someone who has a right to vote, and would pass the inner envelope to be opened and the vote counted by another person. With a process that includes randomly selected witnesses, it should be possible.

But, since all voters need to either vote or justify why they didn't/couldn't, the need for such systems is much diminished.