Most (though not all) of the ka-Booms I've seen documented didn't involve the barrel/chamber bursting, so I am not sure the thickness of the chamber walls is the real root of the issue. Normally, the case bursts and most of the gas shoots out through the mag well, blowing out the magazine but rarely injuring the shooter.
I am not aware of a SAAMI spec for a +P .40, though there are some smaller companies using this designation, perhaps for marketing purposes. I think we are all aware that some handloaders routinely exceed SAAMI specs on their handloads, but any resulting ka-Booms are their fault, not the gun manufacturer's. I have never recommended +P .40 ammo.
I do not accept that any reputable manufacturer, Glock or otherwise, would produce for our exceedingly litigious society any pistol they knew to be dangerous with correct factory ammo meeting SAAMI specs.