I've created a tracking issue (https://github.com/lat9/usps/issues/38) on GitHub to reflect updates associated with the USPS Ground Advantage shipping method's introduction.
As of today, the USPS test server *still *doesn't return quotes for the new USPS Ground Advantage shipping method. Until that time, USPS says that they'll be returning USPS Ground Advantage rates for all First Class and Retail Ground quote requests. As such, I'll hold off with the **K11i **release of the shipping module until such time that USPS starts recognizing that shipping 'service'.
Note that the **K11i **update will result in all "First Class" methods' removal and the "Retail Ground" method's renaming to "Ground Advantage". Since there will no longer be any "First Class" methods, "USPS First Class Filter" setting will be removed.
The **K11i **update will, due to the available methods' restructuring, require that the USPS shipping module be removed and then re-installed via your admin's Modules :: Shipping tool. This is a heads-up to site owners/maintainers using the USPS shipping module so that you can proactively note the current settings!