Presently our system uses - KNOWNSPELLS:LEVEL=x to grant all spells of a given level to the class.
All casting Archetypes seem to have this thing where they will either remove this function, or alter it.
To fully Support the Archetype's which completely remove all Cantrips or other spells, we either need to expand the function, or create a new tag.
What is required today:
If PRExxx met, you get the Known Spells.