I have been a poll challenger for the Michigan Democrats the last two elections 2018 & 2020.

During the 2020 election I was at the precinct the entire day from 7am to almost 10pm. I had two Republican counterparts during that day, one in the morning until about 1pm and the other showed up after 2pm and left when the polls closed. He did NOT stay until the tabulator was finalized.

I wrote this article based on my experience that day: https://medium.com/@dennisbmurphy/problems-created-by-write-in-selection-by-voters-on-a-michigan-ballot-7aea1b274a78

In both cases, the Republican challengers hovered over the poll workers looking at signatures, which is stupid. None of us are handwriting experts. In any event they never challenged anyone. I viewed my job as to challenge THEM if they did, not to challenge voters.