Weather Sealing is a Gimmick.

As you correctly point out, you have low odds of winning a warranty battle with a camera manufacturer about whether you over-tested the weather sealing.  But, with many years of experience behind me, I can tell you that it's not as important as a lot of people believe.

I shoot in the rain a lot - landscapes and cityscapes are gorgeous in the last few minutes of rain, when the rain is gone enough that it doesn't obscure or create distracting streaks.  Long experience has taught me that in less than an hour after the rain tapers, things start losing the fresh, lush, saturated look.  So, I've had every conceivable type of camera out in the rain - and fog, and freezing rain, and blizzard, and ice storm, and "wintry mix".  I shoot the pictures without concern for water hitting the camera, but keep my camera close to me and semi-sheltered in between shots, and keep the lens body, where the lens connects with the camera, and the top controls reasonably dry by wiping with a small towel or cloth every few minutes.  Once I'm done, I dry it off well once indoors.  I can be out for an hour or two before it completely stops, and in winter storms, three or four hours.

A couple times I've been shooting in ice storms where enough ice built up fast enough that AF stopped working, because the coat of ice locked the focus ring (which still rotated with AF) in place.  Broke the ice, shook it off, dabbed off the water, and kept going.

I have never had a problem with water damage to a camera.  Some weather sealed, some not.

I've also shot in sand storms - sometimes intentionally, but generally not (sand in wind hurts a lot.)  I keep the lens sheltered with a lens hood, and again shake dust off, brush it off, or shake it off.  Never had a problem.  I've seen the insides of a couple of my cameras when having a regular check up tune up, and I've seen powdery dust in both sealed and unsealed cameras.  That said - no failures.

For me, it's hard to imagine a situation where weather sealing would help, and where a non-sealed but well assembled tightly camera body would fail.  Kind of have to shoot hundreds of thousands of frames in the rain, like a pro sports photographer, but if you watch them, they've got "raincoats" for the camera and are drying them all the time.

More important to worry about lens quality, data file and sensor quality, and accuracy of AF and exposure.