- Golf clubs specifically (and most sporting equipment) actually goes down a different pipeline in most airports, since generally this stuff doesn't behave well on conveyor belts.

- Data driven approaches can tell you a lot just from visual information, usually about deformability of objects, but also about expected centers of mass, etc

- Part of the reason we're using single big robots is because you can use heavy duty end-effectors - grasp all the way around the object with a grasp that's predicted to be robust to these kinds of perturbances, and then use quick feedback to safely execute a plan to place it

You're absolutely correct though, that there's a long tail of things coming through and that some objects are very, very difficult. Our problem formulation then becomes identifying confidence in graspability, and deciding explicitly that we shouldn't attempt to grasp some object and should instead flag them for human handling.