That certainly solves the problem of no rate being returned and cart abandonment.
I use the product_groundonly option to prevent USPS shipping from being offered on certain items that are prohibited by the Post Office. As a result potential buyers that are not logged in or haven't entered a State were getting no shipping quote at all and leaving.
That's a bad thing....

My problem is this all could be a non-issue if UPS would auto-populate the state based on the zip code instead of returning an error code. They already do that with their clunky Worldship software and it seems to me they could easily do the same here. Then again, we are talking about UPS.

Thank you once again for the time and effort you've put into this!