I'm not brushing or spraying any paint.
It takes good paint to stick to titanium rod, so you should first rough up the metal surface, then dip it in some kind of white epoxy paint. Once that is completely dry, then you can dip it in glow-in-the-dark paint that contains strontium aluminate. The white color of epoxy acts like a reflector, so the glow appears brighter.
Unfortunately, all of the glow-in-the-dark paint that I have is latex-based, so it is not very hard when dry. I try to beat that a little by coating it with some clear fingernail polish.
If you erect your shelter before sunset, then the glow-in-the-dark paint will collect some sunlight, and then it glows better. If you wait until after sunset, the glow won't be as bright. You can always shine a flashlight on it, and that helps a bit, but an hour of sunlight works the best.
Now, if you think about this... where should the paint be, exactly? If you paint the very top of the stake, it may be impacted by a rock used to pound it into the ground. However, somewhere near the top will be best for visibility. I generally dip mine for about one inch, but I don't concentrate on getting the very top spot covered.
If you do this, you should be adding a negligible amount of weight to a stake.