I keep a Riftia refugium to take care of excess sulfide in my tank.
I am sure that H2S may be responisble for some tank problems, especially when old sandbeds are accidentally disturbed. But H2S is an unlikely culprit if the mechanism is slow release from the sand. It is so reactive with O2 that very little will make it far from the bottom of the tank. I spend most of my time beating my head against the wall trying to get the 2 to coexist so we can keep our animals alive at work. All the bacteria that love that mixture don't help things either.