Hello, we're a local craft fair going online due to Covid-19. All our vendors will ship orders from their own studios to minimize contact. We're running into big questions around how to set up shipping as we have 70 vendors, and therefore 70 locations. We'd love to have a customer be charged a flat shipping rate PER VENDOR. Ie. If a customer orders items from Vendor A and items from Vendor B, how can we get it so the customer just gets charged a flat rate shipping amount once on all of Vendor A's items and then again on Vendor B's items? We're really banging our head against the wall on this one as it seems there's no way Shopify can allow for 70 locations. Any help is truly appreciated!