I don’t understand how a state government can make the USPS do a single thing with mail sent by a 3rd party (constituent).
Assuming the ballots are in official return envelopes, the state is paying for the service. They are both the shipper and the receiver in this case.
I’m sorry you missed the federal court order on this; if PA didn’t provide the account number for express, USPS would have to do it anyway.
What I object to is seeing ballots for other states get expressed from my plant. You just know that they’re registered to vote there because it’s a battleground state and mine is safely in one corner.