This cart gives me access to all the code as well. I can change anything. As for your question about the multiple boxes. For example, we have a scale. The base is very large with box dimensions that must be taken into account and the weight indicator is very small and goes in its own box and uses actual weight for shipping charge. The multiple box feature allows shipping rates to be accurately charged and it shows in our records that the shipment contains multiple boxes. This cart also gives me the ability split orders if the products need to ship at different times. They also have 24/7 support and tons of other features that we love. I did look into your solution, but they just didn't have enough information or a good way to contact them. I couldn't find any info through searching their company either. I am very glad they work well for you and your website, but they just didn't seem right for us.