I agree with letting Jayson play through the bumps but when it's obvious he doesn't have it or lost his courage in big games then just don't play him as much.
I also think that he should play it through, but sometimes winning comes first, and if he plays bad, he gets less minutes and doesnt get the chance to get out of his funk. In turn his confidence takes a dive anyway. That's why it made me consider just let him dominate G-League and maybe he gets confident. It worked for AB, it could work for Tatum.
Not saying its what I would do, but its a consideration if I was in charge. (of course I am not, so relax)