No you are right, the sun is not a HPS. It is far, far more powerful and intense than an HPS. You can still get results with light leaks, but you will get better results without them. Don't be a lazy douche bag, fix your light leaks if you have them. All it takes is an extra layer of 6 mil black plastic and some duct tape.
Roc-Lon Black Out Lining is great.