If there was a dead cylinder, wouldn't it be blowing the pan at any engine speed? He only cracks the pan at WOT

My engine cracked 2 of them, one was a used original so I thought maybe it was already weak, but a week later the brand new one did too.

Only at WOT

I checked my breather (remember, PCV only works when there's manifold vacuum, at WOT it closes, so the only way to evac blowby at WOT is through a breather). And I could barely blow through it by mouth. I pushed open the metal more (it resembled a pop can that was just cracked open) and then removed a big wad of padding. Replaced it with some paper towels to catch any oil vapors and never cracked another pan.

At engine idle, air would suck in at the breather, which is another check the OP could do... Of it was cracking from excessive blow by due to bad rings, hole in a piston, etc, wouldn't it be lightly puffing out of the breather at idle?