I was thinking about the McCormack Rig just now and realised that with a soft mast/torsion bar and a low boom, it would be possible for the boom to hit the box with the mast bent and the sail half eased. All sorts of rule and physical measurement problems swept across my mind.
I then took another swig of coffee and realised that the designer of such a boat would be mad - it would be unable to let its sails out. It would never come near a measurement box, let alone cause a problem to the stability of the rule.
Nit pickers of the rule would be well-advised to look at whether any apparent gap or inconsistency actually represents a practical engineering problem.