The AC integration unfortunately sees adding to a list as creating a new contact, but adding a tag does not.
This keeps members from being able to add to a 2nd list. I know the workaround is to add tag and create another automation in AC to add to another list, but this adds a bit of confusion and more work for the user.
Requesting ability to Update contacts in AC through the workflow, not just create them, like how the tag works.
Thanks for considering!