You have to weigh the good with the bad.
The secret ballot is essential, as compromise of that secrecy enables vote selling and voter intimidation. One of the reasons New York had tabulating machines and kept them was to limit the ability of political machines to interfere with elections at the local level. Tammany Hall operatives and others would retaliate against voters who didn’t do what the machine wanted. (Later those machines aged and became a liability)
There’s no such thing as a perfect process, and while your idea is a worthy way of providing validation, it creates more serious issues that ultimately undermine the democratic process.
If you have any kind of audit background they answer to ensuring integrity is always a same: a well defined process where different individuals are responsible for different parts of the process and are audited to achieve best practices.
The reality is that measures designed to target individual voter fraud are solving a problem that doesn’t exist and are done to suppress turnout.
The actual risk of voting related fraud is pretty obvious - political partisans with the access and ability to intimidate or bypass civil service employees from following the process. As a nation, we should be lauding the courage of the GOP election commissioners in Georgia who risked their careers and perhaps their lives to defy a demented president. Whatever the politics, those are people with integrity.