Michigan’s machines that we put our ballots in do not reject for leaving a blank spot for an office. It will reject if you try to cross party lines or fill in more spaces than asked for, but they DO NOT reject for non-vote. I see your point for none of above, but dems would that up, too.
I want to know how Screaming Look-at-Me knew about ballots where president was supposedly left unmarked. That sort if thing should be private...
Each machine records a number of "undervotes." It doesn't single out any particular voter or ballot, just the number of voting sessions where voters used the machine, but didn't select a candidate for a certain office. At least that's how it works in my district.