Currently there does not seem to be a way to delete a device from your account/assigned username. If you have to exchange or return a device that has already been linked to your account, you cannot delete it without emailing support. An updated app should include a way to delete devices from within the app itself that you no longer own or have in your possession.
I’m currently going through product suggestions, and wanted to let you know (if you didn’t know already) that this feature has been added to the app. You can check it out here! I will be locking this topic, if you have any questions about it please feel free to PM me.
Thanks for the input- happy posting!