Hello,
although this is a rather old post, here is at least one response.
In order for your custom permission to work you need to apply it to a node that is a primary ancestor of the person node. E.g. you would need to authorize a user either on a specific person or the container of person objects (XPath: /system/people). The "type" parameter on a permission set only specifies that the permission groups you declare are applicable to a certain type, not automatically applied. Granting a permission group to a user only grants the included permissions within the context of the hierarchy defined by primary child associations.
Regards
Axel