Can this be thought of as a priority chain or is it more like a template? Is there any thinking about exactly what we should choose for tenants, or is it mostly by institution request?

What are your thoughts on always preferring `persistent-id` over `eppn` given `persistent-id` is more anonymizing? Assuming we are looking to other mechanisms (e.g., a user-mapper with shibboleth attribute data) for user mapping, it would make sense to default to using the safest ID mechanism possible in this instance.