An on-prem license gets bound to IP address, MAC address and hostname. IP and MAC may not be known for the docker container and therefore a different license model is necessary but likely uses docker-specific details for license binding.
Support will allow you to get new licenses to flip between, but you really should have some kind of plan and then stick to it. Plan changes are necessary, of course, and Support will help you address the change, but they're certainly not going to want to address flip-flopping...
