I think electronic OCR sorting machines are OK, where you put one pile of paper in and get multiple piles out, e.g. Republican, Democrat, Other / Errors. You ca

I think electronic OCR sorting machines are OK, where you put one pile of paper in and get multiple piles out, e.g. Republican, Democrat, Other / Errors. You can quickly flick through the piles and check they are all the right candidate. You can quickly see the size of the piles, so you can be fairly sure right away that the count is correct. If things are close, you can recount and verify the piles manually. Anything that doesn't do that (even electronic counting of paper ballots) cannot be trusted.