Bill, re your post 42 you wrote:
"The information on their request would be checked against their voter registration record, and their eligibility would be verified before the ballot is mailed."
When I voted by mail during Covid, my ballot was placed inside an envelope, which I then sealed. On that envelope, I could enter either my driver's license # or the last 4 digits of my SS# so my voter eligibility could be confirmed BEFORE the ballot was processed. I entered my choice, signed it (when I vote in person I have to sign the line next to my name on the voter roll), put it in another envelope, which I then sealed. I then put that envelope into another envelope to mail it to the county courthouse to be processed.
I could follow the processing of my ballot online. I mailed it on a Friday, it was received on Saturday and processed on Monday.
I am sure that every state follows a similar procedure for mail in ballots.
Of course, Mr Know It All, you can always Google MN absentee/mail ballot instructions or go the the MN Sec'y of state to confirm.