Agree with post 21. Also,they are verifying every single voter, as well as, documenting the number of votes vs. the number of voters.
They’re doing a lot, including visiting addresses to see if they are empty lots, office buildings, etc.
I was thinking of doing subtle things like finding the mail-in ballots without folds, folding them, and returning them to the pile. That would “mark” them as possibly legitimate. They’re checking for un-folded mail-ins.
If a mail-in has no folds, it couldn’t fit the envelope, so wasn’t mailed.