Thanks for sharing your experiences! Did you notice anything during the time up until it snapped, or was it out of the blue? This is a great fear of mine; a sudden failure while on set oping.
I feel the same way about the arm. Every time I've flown a bigger build, 18-19lbs, I still have a lot of room left in the arm to go heavier.
I'm not sure if any other gimbal fits the Zephyr or Aero sled, I think our post is one inch?
If you find yourself always pushing the limit, it might be time to upgrade the rig!