While metamagic is a causal level below magic, meta-cognition is a causal level above cognition. You cannot really dictate the state of your neurons through meta-cognition. It seems to me extremely unlikely that something very valuable would come from this.
Are we overestimating the importance of meta-cognition?
In any random given magic system that wasn’t balanced against this, focusing yourself on Metamagic is a semi-reliable way of finding gamebreakers.
I daresay nobody balanced the Universe.
While metamagic is a causal level below magic, meta-cognition is a causal level above cognition.
You cannot really dictate the state of your neurons through meta-cognition. It seems to me extremely unlikely that something very valuable would come from this.