LOL! I'd almost made a nasty wisecrack about that P&Y letoff thing and thought better of it before I posted. [8D]
I don't doubt you've not seen any ill effects from shooting very light arrows. For a while there, you were changing bows more often than I changed underwear. [:-]
(I have noticed your new bow acquisitions have slowed down a bit since you became a family man
) Not all bows will have a sudden, violent failure within a few shots with exceedingly light arrows. The damage does occur though and it is cumulative. Sooner or later, the bow will fail. The lighter the arrow, the sooner the failure.
Maybe the reason we don't see many complaints about excessive wear and tear is because we see so many posts about folks buying the latest, greatest bow every year. Some of these guys buy several new bows every year!
I intend to shoot my ProTec until I hang up archery, so I have not shot an arrow less than 7.5 grains per pound with it. Most of my shooting is at 9 grains per pound. If it's as good a bow as my old Hoyt's, it should still be shooting great for the next 10 years at least with that arrow weight. It will probably outlast me.
As I said above, mfrs had to beef up their designs in order to keep from going broke while warrantying bows for 5 grains per pound, which allows the AMO chart to remain fairly viable even though the energy levels have taken a quantum leap. And they certainly couldn't stand a personal injury liability lawsuit so, yes, there is a safety margin figured in there.
Frankly, I think it's a fool's errand to go under that safety margin. If it scares the mfrs, where all they have to lose is money, it should scare the pants off the archer. Archers have a lot more riding on that safety margin. Maybe they'll be lucky and won't get hurt, but they could just as easily be blinded or crippled for life. I've heard of at least one death that was attributed to a bow blowing up, where the shooter's skull was smashed by half of a riser.
I doubt knowing it was a freak accident was much comfort for that shooter's family.