First make sure you understand the size of the "folding snorkel" so you know what it will require for storage, initially while you are diving and finally in your scuba closet where it may ultimately end up.
I've got 2. The scubapro folds once and is not much easier to store than a regular snorkel. If crowded in a pocket, the mouthpiece may eventually be damaged. I found an apollo folding snorkel. It is a soft tube that give you a few folding options and the mouthpiece is not as vulnerable to damage while stored. But, on the one I found anyway, the o-ring between the mouthpiece and the tube leakes a bit resulting in wet breathing. I'm going to replace the o-ring which really looks OK to see if that helps. But I'm afraid the problem is a seam on the hard plastic surface that has to seal with the o-ring but doesn't.
I carry a standard snorkel stored on my BP between the plate and the wing.