Main cap girdles re-discussed

There seems to be a popular opinion that none of the comercially available main cap girdles for a SBM are proven to be effective in preventing catastrophic engine failure.

My first question is, at what point are these engine blocks/caps *actually* failing?

I'm interested in anyone's first hand observations and confirmed anecdotal experiences.

(Ie Not that your cousin's friend's roommate's boyfriend says they fail at *** hp.

The internet is notorious for false or misleading info to be repeated endlessly despite not being factual)

Secondly are these engines failing because of lack of crankshaft centreline control, or is something else in the block moving/flexing/breaking/vibrating/harmonics *before* the crank/caps are spat out, and the damaged caps/saddles are caused by something else being insufficient?

I truly can't see how a main cap girdle wouldn't immediately add both structural integrity and vibrational dampening to the main caps and crank saddles.

If you were to get a junk block and set up a dial indicator on a tightened main cap, and smack it with a hammer in either a left-right axis or front-back axis, it would certainly absorb a certain amount of kinetic energy and move the dial indicator.

I'd almost guarantee that doing the same with a main cap girdle installed, that measurable movement on the dial indicator would be reduced significantly, since the energy is now absorbed by both the area of the girdle and the other 4 main caps.

But let's say for curiosity's sake that the commercially available girdles currently offer no advantage at all.

In this case, what improvements would need to be made to create a highly functional main cap/girdle package that would allow a SBM to live happily at 1000hp or beyond?