I think it certainly helps with flavour if nothing else, but I don’t think the extra degree or so in temperature would make much difference.

Though saying that, I’m now wondering to what extent rice cooking would be affected by high altitudes — I had a friend who lived somewhere high altitude in South America for a while, and she said that the low atmospheric pressure meant cooking certain foods was difficult because the water boiled at a lower temperature (I wish I could remember more specifics)