If my cook is going RIGHT I don't foil until they are resting. Which is 250, clean blue smoke the whole way. If the wind says hello and raises my temps I'll let them go to a color I like, wrap, and let the temps go all the way to 330 if they wanna go there. I don't like choking a fire while I have unwrapped butts on. I don't like the taste.
Just what I do.