I think it might have even been in this thread where I relayed my experiences with using a mobile BP as my excuse to put it away, then having my phone snatched out of my hand and tossed into an open, exposed bin through X-Ray while I was left to wait my turn for the WTMD. Needless to say, I've gone back to the paper BP option.

As to the first part of your post, your whole argument is based upon a false assumption. You assume that common sense prevails during gate checks. In my experience, common sense is shoved further back during gate checks than at any other point in the process, as the TSOs tend to go through your stuff especially thoroughly at the gate in hopes of catching something their checkpoint drone buddies missed. I always laugh when I see a water bottle purchased post-security confiscated at the gate, then thrown into the trash can right next to the GA's kiosk. That's totally going to make the whole terminal safe from the deadly bottle of water!