I've got 2 P guns, and 5 other guys I know who are friends also shoot P guns. Most of them have 2 apiece. None of them have ever had ribs that loosened so perhaps that's just another internet rumor? It does get hot here, and during the summer months I wear a glove on my left hand to keep from getting it burned when opening the shotgun to eject fired hulls. It gets that hot.
And with respect to the V spring thing, I believe I posted this before, but I'll do it again. I got my first P gun in 1974 and 100 rounds later, the V spring for the top barrel broke. I replaced it and decided that was a weak area, so I bought 2 spares for the top barrel and 2 spares for the bottom barrel.
I've still got those 4 spares in my parts box (knock on wood). I have seen one of my friends break a V spring, though, around 2 years ago. He carried a spare trigger assembly and just switched triggers and replaced the V spring when he got home.