Sorry James but you are wrong, in my shop I do have a box of broken toggles,pins, bent pins, elongated or broke out toggle buttresses, have handed some guns back to their owners telling them that they now own a boat anchor (two in particular come to mind that had developed .045 headspace, one fired out of battery because the extractor claw held the case far enough out of the chamber to allow an unsupported case explosion, one quit firing because the firing pin didn't reach the case when chambered) and I do have an acquaintance who was carted off the firing line (Quigley match) to the hospital by a good friend with the rear of a firing pin stuck in his eyeball from a toggle action.
you are right that all the new guns are made from modern steel and you would think that with modern cnc machining that they would all be cut the same and equal in all aspects...but there in is the problem... they aren't. The problem is that they are all still 1873 designs and need tolerances to work...these tolerances allow movement and fragility of the moving parts are their downfall. The fact is that some with tight tolerances can stand a round or two without breaking or even 2 or 300 without a problem but it is a Russian roulette game with any toggle action with anything more than a medium loading. Remember, metal fatigue can happen immediately and catastrophically or it can happen accumulatively over time...
All of the above pertains to Italian makes, however, I have unboxed a half dozen new Miroku's in the last two years, I love them, very nice guns BUT when you take the side plates off they are built with the exact same tolerances as the others. Enough so that I won't be playing roulette with one...that Winchester man might be right...or he might be wrong and your the one that will pay the price...not him. Why save for months and spend hard earned money on a $1800 gun just to prove someone else was wrong. If you want to shoot strong ammo use a proven strong action. To do otherwise you are a danger to yourself and anybody else on the firing line at the same time.
Incidentally I have never seen a toggle action that has been short stroked with an over torqued anything...quite frankly, their owners treat them with the respect they deserve.