I would be nice to support shipping overrides as per https://sellercentral.amazon.co.uk/gp/help/help.html/280-9105200-9401661?ie=UTF8&itemID=200212820&language=en_US&ref_=ag_200212820_cont_200259180&
So (In my case) in magento products which have higher shipping charges can be catered for - you could use fields for the necessary data