Board Thread:Theories and Speculation/@comment-36649908-20180820043133/@comment-33485854-20181027055713

There is a narrative reason as we don't know what the Jogan as it is a seemingly new Doujutsu. But that doesn't excuse them for not defining it for so long. Doujutsu do work similarly in the most basic sense, pour Chakra into your eyes. We've seen Mangeko Sharingan users take to their unique powers naturally, innately understanding how their techniques should work and then refining their control over said power. We should have scenes of Sasuke, Hinata, or even Naruto working with Boruto to figure out the eye's powers and limits.

If the powers suddenly activate in a life or death as a solution situation it is going to feel like an asspull. The Sharigan has the excuse of the eye reacting to strong negative emotions through chemical reactions in the brain so they can't just keep reusing it.