Pain is one of those things that can be replicated in a dream. Anything that can be replicated can also fail in a dream or pass based on the dream itself or your belief of whether it will or wont lol.. You can mostly only rely on bodily rcs that most likely would not fail or pass based on what is really going on physically and nonphysically.. such as being able to "physically blow" past your "nonphysical closed lips". Or breath "physically" though your "nonphysically closed off mouth and nose". Breathing is the most reliable because we can control it, and do control it the same, whether we are dreaming, or not dreaming, and in both of these states we can consciously control it.