These materials represent the Incarna i20™ approach based on d20 use.
The character chooses focus narrowly with the class based model in order to gain additional intuitive understanding which translated to more spell slots. Breaking any requirements immediately removes all benefits and returns spell slot progression to normal. The character must forgo any chance of Multiclassing, use Aptitude for d20 and commit to a single Mystic Tradition, their Spell Slot progression at high levels improves. Any level which # of Spell Slots repeats > 4, the 5th time add 1. Apply recursively too, if that +1 value repeats > 4, etc.
Example: If the Spell Slot progression is 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5 it would become 4, 4, 4, 4, 5, 5, 5, 5, 6, 6, 6, 6