Commercial Usage of Ubuntu Core

Dear all, I am evaluating the idea of designing an IoT device where the operating system will be Ubuntu Core plus some proprietary snaps we are going to develop. I understood there is a pricing plan for the usage of the brandstore but in case we decide to implement autonomously the remote upgradeability of the snaps hence without using the brandstore do we still need to have some kind of license for using UC in our commercial product? Thanks!