So true! No federal charges will move forward for quite some time.
Refusing to return them isn't an official act because he was no longer in office, therefore nothing he did or refused to do was official. BUT you're right his lawyers will easily stretch that out past the election. If he wins, he'll put some sycophant in charge of justice & tell them to dismiss all charges.
The 34 convictions can't be touched unless they are separately taken to SCOTUS. Same for Georgia charges.