Choose which list Shopify contacts are synced into

The auto-generated lists in the Shopify Integration are nice, but I already have existing lists that I use to communicate to customers. I like the contact-syncing feature but since I can't select an existing list for new Contacts to sync to, I still have to go into Constant Contact and assign the new Shopify Contacts to the lists that I actually use. If I could designate an existing Constant Contact List for Shopify to sync with, I wouldn't have to do this extra step.