I've never really thought of it as a safety issue, but having thought about, I think from some personal experiences and what you have said, I definitely think there is element of truth in it. I've never really had any serious issues from wedgies but there have definitely been times when I have had to stop for quite a while because I would up end getting really sore and it would hurt for a few days. I really don't enjoy it, when that happens. That's why I tend to avoid harder wedgies, such as hanging wedgies, theses days. So I do definitely agree with you that there is indeed a need for good safety to avoid all the nasty side effects; and also I don't want to do any damage down there. It has been something that has concerned me for a while but I've never really known what exactly I can do about it.
For me, personally, I want to try and get into permanent wedgies. But most of my attempts have been unsuccesful so far. I guess, I just haven't found or mastered the right technqiue yet. I would like to last all day; the best I have managed so far is about an hour. I have always found it impossible to last longer; I don't think it has anything to do with my willpower to handle the wedgie. I just find it ends up being unberable and "too uncomfortable"; in fact I would love to be uncomfortable all day from a wedgie and I would much rather it be an annoying discomfort rather than something that was truly unbearble and too much. I don't know if I am describing this right, but I'm sure you can figure out what I mean.
My thoughts are it has to do with the type and style of underwear used. I have discovered that certain types of underwear have been less of a problem than others; though I still do think that eventually you still do end up with some sort of problem coming up. I think your thought on it being a pressure problem is correct and I think that is mainly where the problem is; though I could be wrong and it might involve more factors. I don't know how well different styles/techniques would work for different kinds of wedgies; I don't think there is going to be one solution that will work across the board. What would work for a permanent wedgie might not work for a hanging wedgie but it would be good to get a general idea. I think in terms of something that might work, I think it might need to be some kind of underwear that goes between the crack in a loose way; I am thinking in between tight and somewhat loose. I think I might have a few little theories but I would like to hear what anybody else thinks.
I am thinking about creating a thread for the discussion of permanent wedgies; I think might be good to maybe have something seperate for anyone who want to discuss that.