I can only speak for myself...
Sometimes I "play with porn", maybe not very often, because I want to save orgasm for my wife! If I masturbate, I'm fried for a week (with niacin, 3 days with viagra). I mean I don't have POIS, or little POIS, but I stiil can't do it again for those days. So if I masturbate, no sex with the wife (which I prefer.... and of course so does she).
So if I play with porn, I have to be very careful. Sometimes I come close, but stop before anything more happens. I feel "heavy" in the groin area, butit ususally passes within one or two hours. Nothing more, no cognitive or other symptoms.
The others will have to answer for themselves. Some have no ill effects, others mild, others more severe. My feeling is that most almost always have lesser effects than full orgasm, even though the effects may last for a day.
Sometimes I "play to the extent of having mild "leaks", but never POIS as such. When I "play", it's always "without niacin or viagra prtection". I don't expect to go that far. If I ever went too far, I'd be fried".
I suppose it's come close at times.... especially without niacin, I seem "very sensitive", and could "cum" at the drop of a hat.
With viagra, it takes ma a long time to have the orgasm, (much more staying power) I don't need to fast, and the POIS is less. It's a miracle.
If I don't take anything, I'm 10 days in POIS. days 2 and 3 with borderline anxiety attacks and sometimes depression. Cerainly zero motivation! Niacin has been the only way I can press ahead with the forum, maintain it and maintain the energy to moderate, and control SPAMMers. I wish everyone had my luck.
It's really a bummer with some.... there's nothing I can do... sigh!
(Other than push for professional research)