Yea I noticed the same thing if I hang with too good of a head swell! But because I'm a dumbass I just keep going!Also since I started doing tension stretches I started getting such small dots/spots on the glans when my grip is far from perfect, i.e. squeezing too hard nearly at the glans, while there is some trapped blood. Nothing too worrying here either, I just have to be more careful how I grip when I stretch.
Sometimes the spots are no more then very small, barely noticeable red dots. They appear from some small blood vessels getting popped probably from the pressure that builds when I squeeze harder. A good way to heal a bit faster is to apply heat and massage lightly, also I think some edging may help as it promotes better blood flow imo.
But I do agree with you about the edging, edging does promote the better blood flow and is only beneficial in these cases!

