Reversing the stock fan can make a difference, although not a big one, because it usually makes a difference when there's a deficiency with the airflow, which it obviously can't repair. But as it is, it may help not to be pulling the hot air that stagnates there, but rather to push it away, even if it doesn't exactly solve anything. Probably with a better airflow you would see a more significant drop, would you use push or pull. Each case is specific, and generalization is not helpful, though. Don't worry about it anyway, it looks fine to me with these temps.