The electrolytes for me are more about keeping the body from going hyponatremic. Maybe a little about absorption in the stomach for what is being put into it. So pure water in the bottles and nothing else to eat or drink could get to be a problem if 5 or more bottles are consumed in a short time. When it's 95 - 100°F and above here, I can go through a 25 fluid ounce bottle in less than 30 minutes.

I too use to think it helped with cramps, but even my experimentation with it was too ambiguous with results. Cramps from hot weather seem to be more about whether or not I got my body use to the level of exertion I wish to put into a ride in those high heat environments.