dpi
Provide more granular registrations permissions
Something like <operation> own/any <event_type> <registration_type> registrations would be more helpful than just the 'Administer all registration entities' permission.
<operation> own/any <event_type> registrations exists already as event type access [defaults].
What problem are you hoping to solve with your variant?
Also, this can be implemented using standard Drupal entity access hooks, and doest not require a feature built in to RNG.
So how would I go about setting up that an authenticated user belonging to a particular role can view their own registration but not other registrations?
OK - I've figured this out. I was being dumb. What I need is achieved with the event access rules