How can we stop NetSuite from putting too much weight into one box??

We have 19lb items.  We put up to three of them in one box.

We set the weight to 19lbs in NetSuite.  We found that quantities of 1,2 or 3 of these 19lb items comes out fairly accurate... or accurate enough.  Quantities of 4 or more are ridiculously over charged in NetSuite.  This is because NetSuite automatically assumes that all of the items will be shipped in one box.  When you put too much weight in one box, UPS send it's rates through the roof for a penalty of shipping oversize or over-weight shipments.

To prove that this was the problem, I did one test where I put 4 of these items on a SO.  NetSuite wanted to charge something like $65 for UPS ground shipping.  I then made a new SO and put the same items on the new SO, but I broke them up into two line items of a quantity of 2 per line.  So, two of each item rather than four all on one line.  I set the first two to ship from location "A" and I set the second two to ship from location "B" ...essentially forcing NetSuite NOT