Before you spend your (or the customer's) money, ask the AHJ (Authority Having Jurisdiction) for guidance.
The best way to deal with a government agent or other self-important authority figure is to ask, diplomatically, to be shown how "the other guys" are doing it. Ask the building inspector who will sign off on the job what method the guy down the street is using that is acceptable. Then follow suit.
Ask the elevator contractor for advice, too. Since they deal with this situation for a living, they will probably have an answer. Maybe not the right answer...
I speak from both sides of the argument, being an electrician AND a code enforcement person.
