If I can turn out long pigtails with the fittings already soldered to the ends, this prevents heat transfer. Most times in a wall though that is impossible.
I always crank those fittings on till they stop, never by guidelines followed by the mfg.
Over the past 6 months though when I'm dealing with the numerous styles of threaded valves I've been just soldering the fittings to the threaded connections.
I'm not proud of that application but I take the steps to make sure I use new/clean copper fittings along with wire brushing the threads on both. Applying flux and soldering up; pulls it right in.
It's impossible to prevent heat transfer on a taped/doped connection when you are working in a 4-3/4" opening and only have half of that space to get the supply line reconnected.