We have added additional layout slots for USPS Letters (First Class Letter, NonMachinable Letter, First Class Flat, Non Machinable Flat). If you configure this layout to be different than USPS domestic layout, these type of labels can direct print using a different layout.
We have also added a layout slot for APO addresses. Now you can do direct print for APO.
You can set the layouts used by these shipping methods under Setup => Endicia DaZzle.
Under USPS Domestic, there is now a "letter" filter that picks out all orders that uses letter as shipping method.