I don’t know that Pence could refuse to acknowledge what is in the electoral college vote box to be counted. What he could do is to simply refuse to count the whole thing, in essence refuse to do what the constitution says that he as vice president must do on January 6, that is to preside over and direct the electoral vote on the senate side. He could state that since the votes are arguably tainted, he will not accommodate fraud upon the American people and refuse to count and certify the entire electoral count. He could refuse to affix his signatures to any said supportive documents. He simply needs to do nothing and if he does so there is nothing in the constitution that directs what happens next should Pence stand down from the count. It would be a whole new territory.
Pence can refuse to take the certification of the swing states with these ridiculous over-ballots. Again the states should be responsible for their elections.