Feedback about my shipping box calculation approach

I am a developer of a growing ecommerce system and thought I would describe a new shipping box calculation routine I put in place to get some feedback on it. I actually dont have much experience or knowledge of exactly how these other ecommerce system are doing this, like that zen cart, but from what I have seen this has turned out to be a complex problem for other ecommerce systems to solve. Does this system basically do what a thousand other ecommerce systems are doing, or is it "cutting edge", or is it over the top and too much to deal with from your perspective? So far the few customers I have using it seem to love it, but I truly want some outside feedback from a community like this.

In my system's ecommerce features, you define the box sizes the store will use for shipping. Each shipping provider the store supports, such as Fedex, can be configured to use those boxes where you can specify the max weight for a box and its priority in choosing it for a shipping box. Priority one boxes are used over priority two boxes and so forth. Priority two boxes would not get used unless the product wont fit in a priority one box.

I took a public algorithm from the US air force for calculating how to pack pallets and built up this boxing system on that. It was a solid core, but didnt deal with multiple box sizes. Basically, the system looks at the packing weight and dimensions of each product in the shoppers cart and calculates what shipping boxes to use for each shipping provider they want to support. It always tries to use the smallest box possible, but also tries to fit all products in one box. If all of the products purchased wont fit in the largest priority one box, then it will start to break up the order into multiple priority one boxes. If a given product is too big, it will fit the product into the smallest priority two box. So far the code has been working perfectly in real word sites using it. What's cool is that for fedex, an order might be 3 boxes, but for a given international freight carrier it could be one box, and the system deals with that well.

The system keeps track of which products from the order are assigned to a given box for that order and will create labels for each box that can say stuff such as "box 1 of 3". If a box gets lost in transit, the store can know exactly what products were in that box. Also, for shipping companies like Fedex, it can get insurance for each box based on the value of the products assigned to that box. The code also remembers the exact 3d position of each product as it was calculated to be packed. I want to write a flash app that will show an animation of how the products should get packed to properly fit, which may be an issue for certain types of stores that can have a hard time figuring out how to actually properly pack the box.

If the person fulfilling an order decides to pack the order with different boxes, they can provide the "actual boxes" versus the "recommended boxes" to keep it accurate for tracking numbers and scheduling automatic pickup from shipping providers like Fedex.

Each product can also be specified as "product is shipping box" for things that get shipping in the box it came in, or have its own set of shipping boxes. A single product might ship as 2 or more specialty boxes that are not packed with other products in the order.