I really don't see why it's so important for people outside of a religion to know exactly what every specific title and position is for. It's enough that you know they carry weight within their religion for most things you'd be concerned with.
+1. The point of elders getting their custom title in their signature would be to show they are an elder. It is not elder of (religion) because that is implied and they would not sign that as it is not their title, their title is the custom name.
