So in other words, you don't listen to your own advice?
Whether this is a FO or a reef tank shouldn't matter, the fish are adapted to live in warmer waters. Studies done on reefs show that the temps range 80 to 84 with 82 being the optimum temp.
When you alter their normal conditions, even if you are doing so with the best of intentions, it doesn't change the fact that this is not what they have spent the last million or so years adapting to......