In my county in California, the first voter to arrive has the responsibility of verifying that the ballot scanner is empty and that its printout reads all 0's. That person then serves as a witness to the poll workers applying tamper-evident seals to the scanner door and data module.

This takes no more than two or three minutes to accomplish, and anyone with reasonably working eyeballs can carry this out. You lose this scrutability when you introduce cryptographic proofs and multi-step algorithms into the process.