>>With the PI & PII, even if they do get "bumped" in your pocket, when the pressure is relieved, the light goes off--not so with the PIII. <<

Maybe that's a clue. With the Photon 3, I've always kept the "rear button" on auto-off mode by default, so even if it does get pressed, it will shut itself off shortly.

AFAIK, all the Photon 3's had that mode- though the second (really third, there was a switch change and then a chip change) generation Photon 3 makes it more obvious which one it is when you're toggling through them.