The voter will mess this up a disturbing fraction of the time. It will be rejected. The voter will try again, possibly have it rejected again, give up, and go on Twitter to complain about the new system.

Also, I can go to vote, surreptitiously take two strips of paper, use one, pocket the other. I coerce my spouse into using that one, and pocket the one they took.

> It becomes difficult to coerce a voter because they can say any one of the published ballots is theirs.

Maybe for simple ballots. A question including e.g. a ranking of ten candidates has about 3.6 million possible configurations -- more if undervotes or other ties are permitted. The voter can be coerced to fill this out in a specific way to self-identify, and then vote in a prescribed way on another question.

edit: Of course, this vulnerability already exists: the voter could be given that same instruction. An observer of the ballot counting process can tell if the correct ballot was cast.