Given the background description of some cooking related query, summarize the question into a title

I just tried to answer a question about pot roast and looking at recipes I discover one that cooks the meat at 200 degrees in a sealed pouch for 3 to 3 1/2 hours.There is a lot of reason to make a roast such as a prime rib at low temperatures since the inside of the meat will cook close to the same speed as the outside making an even color and temperature to the meat.However, cooking something at 200 degrees for 3 hours will ultimately cook it through and through which is the purpose. But, does it make a difference if the actual temperature of the meat goes past the boiling temperature? Would it be better to cook it in a 170 degree oven since the steam pressure raises the temp to perhaps something just under boil?
If braised meat is cooked at 200 degrees in a perfectly sealed pouch in the oven, does the temperature rise above boiling?