Interesting turn of the scenario. But you're deliberately ignoring so much context and actually pushing a couple of lies as well.
The fact that in the real set of events, the cardboard was placed on the windows because there was an angry mob outside that was banging on the windows, chanting "stop the count" (while curiously, in states where Trump was behind in the votes, they chanted "count those votes"). The poll watchers were given access as well, but they consistently claimed they weren't, even though later in court, several judges ruled against this claim.
Note also that the vote counting never quite stopped, only that some of the workers went home because they're human beings that need to sleep.
Going further, there's the fact that prior to the election, the mail-in votes were forced to be counted dead last. This, coupled with the fact that Trump was deliberately telling his voters that mail-in was rife with fraud, assured that the majority of votes by mail were for Biden.
You left it off with a "an so on and so on", but I suspect you did that to bolster a list that isn't as big as you want it to be.