New USPS APV system

We received notice from Endicia (we still have an old active account with them) regarding USPS Automated Package Verification System. It reads:

"Starting August 1, 2017, the USPS plans to change the way they handle under-paid and over-paid postage amounts for packages.

The USPS will use the new Automated Package Verification (APV) system to verify the weight, dimensions, package type and entry ZIP Code for all packages processed through USPS sorting facilities.

APV only affects domestic shipping labels with a USPS Tracking barcode. Postage with no embedded tracking barcodes, such as stamps or postage printed for Large Envelopes & Flats and #10 Envelopes, will not be affected.

What does this mean for you?
Prior to APV, packages identified as having under-paid postage were rejected or delivered "postage due." Once APV goes into effect, packages identified as having under-paid postage will be delivered without delay to the recipient and the amount of under-paid postage will be deducted from your postage account balance.
When overpaid packages are identified, your postage account will be credited for the amount of the over-paid postage. Prior to APV, overpayments were not identified nor credited."

Will ShipRush Discount Postage be affected by this change, and allow for debit/credits to our account for any issue where the item was mis-weighed or mis-measured?

Thanks!