Utterly simple fix for the USPS form problem (no software hacks)...
Go to the Configuration menu for USPS Autofill.
Set Delivery: Default Shipping from Same ZipCode (Radio Button) to "other"
Set Delivery: Default Shipping from Other ZipCode (If Radio Button set to Other) to BLANK.

then when the form shows an error condition, just click the "Same as return address from above" radio button (or enter a proper zip code) and you are good to go.