Have you ever actually broken a firing pin due to dry firing? I used to do a lot of single action competitive shooting and I always dry fired with snap caps, but I was always curious as to how harmful it actually is. I've never heard of anyone breaking a pin because of it.
It happened to me several times with a Colt Trooper .357 Magnum (the old-style Trooper with the same lockwork as the Python). I finally got rid of it. This had the frame mounted firing pin. I think it happened once with my first Smith & Wesson M&P (Model 10). Thus, I don't like any extensive dry-snapping of revolvers without snap caps. With most auto pistols I don't find this an issue. I did once crack the firing pin retainer on my first Colt Government Model, but of course this is easily and cheaply repaired and I had done a helluva lot of shooting and dry snapping with that gun. I've had it almost 48 years.