What it all comes down to is does it really matter? Who cares what the metal detector in oompa loompa land did compared to the one in gotham? All you have to do is take off your large metal items and run them through the x-ray. Save for a malfunction or bumping the WTMD a metal detector usually will not alarm if you don't have anything metal on you.

Also, me or anyone else you see at the checkpoints does not have the authority or in most cases the know how to change the settings on the metal detectors. I'm not sure who does actually, probably one of those TSA managers you only hear about but have never seen. All we know is if the machine alarms we can't let you go until your clear either by a second pass or through secondary. So spare the "I went through BFE okay wearing this" speech. It doesn't matter.