For Connect/Growth Plans, figuring out a way to make adding on additional departments locked the same way we lock analytics features based on plan. When customer purchases additional departments, we go in on the back end and unlock however many additional departments were purchased.
While prepping for a QBR I saw one of my customers using more departments than what they are paying for. For any of the more tech savvy customers, it is pretty easy to figure out how to create a new department from the customer dashboard. I wouldn't be surprised if there were more customers doing this.