Some carriers (FedEx/TNT in Australia) are charging additional fees when delivering to a residential address, and if delivering over a certain weight limit a significant 'surcharcharge' (can be as much as $170 for > 100kg to a residential address. It would be beneficial if we could restrict carrier options that get returned at the the shopify checkout by weight, unless they are flagged in starshipit as commercial (non-residential) customers (or somehow in Shopify). There are also carriers (in Australia) that do not deliver to residential addresses at all, so if we don't have the ability to determine if they are an option at checkout, it limits our ability to use them as an integrated service.