This isn't a guide or article, just passing info i myself have figured out. It may help others.

TL;DR To anyone planning on USPS shipping items, the best bang for your buck to Region 4, 5, and 6 would be the REGIONAL RATE B2 BOX only available from USPS.com. It is a boardgame shape and fits a whopping 22 analog bags. After that, Regions 7+ use the LARGE FLAT RATE BOARD GAME BOX also only available from USPS.COM.

The Details
I plan on freezer bag cooking. All of my meals half-fill a 1 quart Ziplock Stand and Fill Freezer bag. For my analog, I poured in 2 cups of dog food. Dog food is similar in weight (bit heavier) and volume to freeze dried / knorr / idahoan packages. They are rolled up into soda can shape cylinders. I then took each type of box USPS provides (provided they sent them to me...), and measured how many bags I could stuff into each.

I focused on their FLAT RATE or REGIONAL boxes only as they are the cheapest method to ship and include tracking, hold for pickup (if purchasing postage online) and free pickup.

The box specs are as follows:
USPS BOXES.JPG

16 bags weighed 90oz. The shoe box at the bottom of the table is to show how much it would cost not using flat rate.

Shaking and Shifting the box settles the bags and allows them to fill all air gaps using 99% of the box's capacity. The strange thing is that the volume of the Regional B2 box is less than B1, but holds more. This is due to the shape of the food bags being cylindrical and about 7" wide. There was still room on the sides of the box to stuff smaller items.

Pro Tip for those freezer bag cooking freeze dried meals. give the mylar bags a furious shaking before transferring the contents to ziploc bags. This breaks up any sharp edges off food that can puncture your bag while in transit / hiking.

Hope this helps and if you need more details or want pictures, just ask and I may elaborate or write a complete guide.