I am not sure what you are shooting at with 408.36. The main is the panel is not required per NEC. I doubt that it is a local ordinance since you are saying it is not required. If the contractor or the customer is going to pay for it, give them what they want. It may just give them a piece of mind. If you have already ordered parts, tell them how much it is going to cost for the change. Check you project specs. if the project came with them.