How about to make “Transfer device/project” button in settings of device or project, and after clicking that button, entering username or email of receiver, project isn’t yours anymore, but receivers? You have no trace of it anymore.
It could be used for non-tech users, they just need to open account. Someone who understands more about IoT and Cayenne defines units, sensors, actuators, maybe even triggers and schedule, and then transfer it to non-techie.
It could be good for spreading Cayenne more (IMHO).