It appears that it's easy to add new tags to a given customer - you can do this by uploading or clicking/adding in the customer control grid.
Removing tags from customers? Not so easy. Re-importing the customer without the tag doesn't do it, and there's no "Remove Tag" option.
This is pretty important - you've got to be able to remove the tags as easily as you can add them.
That said, the customer management platform is a fantastic addition to ShippingEasy's functionality. Good work.