Commission Over Shipping Formula

Other day while I was testing CS Cart a doubt came to me about how the CS Cart calculates commission rates that should be used on the shipping cost when we have products with different commissions rates in the same order?

I received an anwer from CS Cart team but this seems so unusual that I had to ask here if my perception is correct.

The answer that I received said that when calculating the commission rate over shipping the script calculate how much each product contribuited to the order value before the shipping. Then, on the freight value, the proportional value of each is applied together with its respective commission rate.

This make me think that if in an order has products with and without shipping, the commission rate from products without shipping will be applied over the shipping, what it's a little weird. Is this correct?

Surrender! Shipping in cs-cart is generally just plain weird.

Basing shipping commission on value of products is pretty meaningless. I.e. 1gr of gold is worth maybe $120 but a 40lb bag of fertilizer might be worth $10. Given most shipping is based on weight, the vendor supplying the fertilizer is getting a much better deal on the shipping commission than the guy providing the gold.