Chicken to me is a special cook, it seems what works for dark does not work for breast
so we need to learn that we cook each separately at the same time. Also what works with whole chicken seems not to work with parts of chicken.
I judge my beer can chicken by temp prob, I do my parts chicken by sight. And sight is a very long time thing to learn, but it does pay off.
Poke prod and tickle parts chicken till you learn what a cooked chicken breast looks like, as well as a thigh does.
Hey it might not be the answer you wanted, but remember, if it were easy, anyone could do it. You want to earn the name Grillfella, get to grillin and become part of the elite.