Big Greener fan here. The side safety, if you’ve seen its use demonstrated how it was designed to be used, it makes perfect sense. It was never intended as a stalking or a rough shooting type safety. It was intended to be used as a stationary safety at the peg or blind/butt. Picture the gun butt resting on your thigh, barrels pointed up, thumb on the safety with your right hand, birds are coming in, flip the safety forward and your ready to fire. For us southpaws, the side safety is better suited for a rough shooting safety, using the index/trigger finger on the left hand to flip the safety forward while walking up to a pointed bird.
Nice Greeners btw, love seeing them put to use like that!