Hello!
I believe I understand the security implications behind why auth0.com cannot be used as a custom claim namespace, but I’d like to know the logic behind the decision of disallowing mytenant.auth0.com as well, as this would be the most logical/straightforward choice for the namespace in almost every case.
As it has been more than a few months since this topic was opened, and there has been no reply or further information provided as to the existence of the issue, we are closing this topic. Please don’t hesitate to create a new topic if this issue is still present, we would be happy to work with you to help find a resolution.