shipping rates overide
Allow manual input of rates per a particular shipping service.
For example, any users of Royal Mail will know they don't give a rate into shipstation for any services, however those services are largely a fixed cost. 2nd class small parcel or large letter etc.
With no rate being returned, no rate is recorded and then the reports showing shipping costs are blank and not useful.
Also for those couriers who don't support sending rates to Shipstation in the way UPS do so well, its a chance for shipstation users to sense check the cost of a shipment before making a label for it.
I accept these aren't live rates, but an inputted rate is better than shipping blind and it would make the reports way more useful as at the moment, without costs they are pretty useless.