Can you ship via non-USPS couriers? FedEx, etc?
For all the supposed panic and importance of this process, the poster didn’t do even a google search of this issue
So on the surface, this looks more like corporate welfare to FedEx/DHL.
Import tax and tariff relies on clear and accurate import declaration.
For DHL/FexEx imported package, you can fine them when the declaration isn't right.
For USPS imported package, you can't fine USPS -- they didn't know what's in package when it arrive. You can't fine Hong Kong Post or China Post, because they are not US entities. Rejecting parcel in bulk is one of the reasonable option if they can't get the shipper fill in the correct declaration form.
Or you could do what pretty much every other country in the world does, and fine the recipient.
USPS forwards packages from HongKong Post and China Post -- they don't have direct relationship with the shipper.
FedEX/DHL, otoh, have their local office in HongKong and China, they help the customer do declaration and inspect them before seal.
When FexEX/DHL package got the declaration wrong, they got fined. When USPS package got the declaration wrong, they are hand-tied.