Never saw that before. All the schrader valve cores I've used do in fact bottom out on a rubber seal, so no chance at stripping. Maybe I just read it wrong.
My point is you could tighten up a sharader valve core enough to fuck it up also tightening a schrader valve core will not tighten the valve because the valve is spring loaded and you know this because no matter how tight you make the valve core you can still bleed off air by just pushing on the middle.
I have had schrader cores fail/stick open from corrosion on a car rim left in a shed over the winter valve side down, or phucked/jammed open from dirt and when I mounted car tires way back in the day we often changed the valve stems as a precaution because it was a minor source of failure