Pence's power was to call for objections, and the members of Congress had the power to object to Electoral College votes.
Keep in mind that this was the "backstop" power, the last resort. The state legislatures had the prior power to question ballots going back to 3 U.S. Code § 2 - Failure to make choice on prescribed day and 3 U.S. Code § 5 - Determination of controversy as to appointment of electors weeks before the ballots made it to Congress.
In fact, 3 U.S. Code § 2 - Failure to make choice on prescribed day may make delayed acceptance of mail-in ballots unconstitutional.
Whenever any State has held an election for the purpose of choosing electors, and has failed to make a choice on the day prescribed by law, the electors may be appointed on a subsequent day in such a manner as the legislature of such State may direct.Since Election Day is the first Tuesday after the first Monday in November, if a state has not selected its Electors on THAT day, this section of the US CODE says that the legislature may choose the electors after that, and not wait for a week for more ballots to arrive and be counted.
This section of US Code could have also been used to invalidate the 2:00am ballot dumps that put Biden over the top because those ballots arrived on the next day AFTER the day prescribed by law. The legislature could have cited US Code Title 3 § 2 to discard those ballots and call the election at that point. Of course, that action would have been immediately appealed to a friendly judge, who would then have to rule on the interpretation of the US Code.
-PJ
“on the first Monday after the second Wednesday in December, members of the Electoral College meet in their respective states and cast their official votes for president and vice president.”
https://www.history.com/news/electors-chosen-electoral-college
So the states had over a month after the ballot dump to choose electors. If they didn’t challenge them before that, it’s over. There’s nothing Pence could do. I don’t quite understand what you’re getting at?