Improved Spontaneous Spellcasting
Mistveil → Rules → Improved Spontaneous Spellcasting
The Sorcerer, Psychic, and the Oracle each acquire new spells known at a rate of class level + one. So the Sorcerer for example, would begin knowing five cantrips and two first level spells and would gain their first second level spell at level three. At level twenty, all three classes gain the following class feature:
Pinnacle of Knowledge
At 20th level, the spellcaster has reached a perfect understanding of their power. They gain any number of spells known whose combined spell level equals two times their permanent spellcasting ability score modifier (level 0 spells count as 1/2 spell level for this purpose). For example, a Sorcerer with a permanent Charisma score of 25 (a +7 modifier) would learn a number of spells whose total level equaled fourteen.
This is a significant buff to the efficiency of these three classes. I incorporated this rule due to my players not choosing these classes to play unless a very specific build used them.