We are frustrated with the manual maneuvering required to process orders and shipping labels in Shopify Shipping. For instance, we don't use UPS as a carrier yet there is no way to exclude UPS as a carrier in Shopify Shipping. This requires us to open up each individual order to ensure Shopify Shipping hasn't selected UPS as the carrier. If a customer is sending our product as a gift and has provided us certain handling instructions which the recipient shouldn't see, we must manually remove the customer's notation so that it doesn't appear on the packing slip. So, we are looking for the best app to help speed up the ordering processing time by allowing us to set certain rules suitable for our business and to process labels and packing slips in bulk. We would like to be able to exclude UPS as well as to print 50 shipping labels at a time on a Zebra label printer while simultaneously printing the related packing slips on a desktop printer. What shipping apps provide the best flexibility and automation?
I didn't a deep research on this, but maybe Massfulfill app suits your needs, If not I'm open to test more options on my own to help you, kindly check https://apps.shopify.com/massfulfill to check the app and maybe the FAQ page is useful to see if it's related to what you're looking for.