Haven't seen another diver use my particular setup.
30 cf pony mounted upright on my main tank on my right side. 3 lbs offset with weight in the BCD integrated pockets. Pony second stage regulator on a necklace hanging below my chin. I have a transmitter on both tanks, with a computer on each wrist (pony bottle computer is on my left wrist). That way I always know how much gas is in the tank, I dive with it valve-open.
30 cf pony mounted upright on my main tank on my right side. 3 lbs offset with weight in the BCD integrated pockets. Pony second stage regulator on a necklace hanging below my chin. I have a transmitter on both tanks, with a computer on each wrist (pony bottle computer is on my left wrist). That way I always know how much gas is in the tank, I dive with it valve-open.