Yeah, I'd want a J switch. Not a permanent J, but I'd become an INTJ whenever I wanted to/needed to. I'd have multiple books published, have started and sold a few businesses by now, I'd probably have a Ph.D.
if the "change one letter of your MBTI type" fairy were to grant me one magical letter-change, I'd ask for a J please. because I labor, I mean, daydream under the delusion that this would make me more successful in the world, if not better-looking.
Uhh.. the letters don't work like that. The 4 letter code has to be deciphered before you can glean anything from it. For example, "changing" p to j means you go from Ne to Ni and Ti to Te... not to mention tertiary functions, etc.