Avoid the 125-grain JHP loads listed at 1400-1450 FPS, and you will be OK for many tens of thousands of magnums. Data is published by the ammo companies. Pay attention, and you will be fine.
You really don't want to be shooting those full-pressure 125s, anyway, unless you really love acting like the god of thunder and lightning. Winchester 145-grain Silvertips are good loads for short-barreled magnum snubbies, and to go milder, there is the Remington 125-grain Golden Saber, and even milder, the Speer 135-grain Gold Dot Short Barrel load. NYPD officers who have used this latter load at .38 +P velocity have gotten good results against real-life criminals, and the .357 version pushes the same bullet just a bit faster. My wrists are getting old, and especially my right wrist does not like recoil much any more, so I plan to try some of this Short Barrel stuff.
BTW, it is not so much cracked forcing cones, as eroded forcing cones. Though it may seem counter-intuitive, it is certain of the lighter-bullet loads, loaded at the higher end of the pressure scale, that blowtorch the forcing cones so mercilessly.
I just picked up a very minty 4" 19-5, to replace the 19-3 and the 19-6 (or 19-7, perhaps) I let get away from me in the 1990's. I like L-frames and GP100s, too, but the K-frames have a lower bore axis, and kick upward less, in spite of their lesser weight. The Model 19 is a truly serious fightin' sixgun.