Honestly, the whole 'insanity equals power' thing with Gojo always felt a bit overblown to me in the fandom. I mean, yes, his personality is chaotic and his mental state is... unique, but the series itself doesn't present it as a direct battery for the Six Eyes or Limitless. His power is innate, a birthright. The 'insane' part is more how he interacts with the world because of that power—the boredom, the detachment, the god-complex. He's so far above everyone that normal human logic doesn't apply, which reads as insane to others.
Where it gets interesting is in the sealing. His overconfidence, a product of that god-like mindset, is what Kenjaku exploits. His power wasn't weakened by insanity; his judgment was. Post-sealing, we see a shift, a more somber and focused Gojo, but his techniques are fundamentally the same. The 'insanity' was a side effect of supreme power, not the source. It’s a cool character flaw that makes him beatable, not a magical power-up mechanic like in some other series where madness grants deeper cosmic understanding.