If what he is asking for is not going to make anything unsafe and it's not prohibitively expensive, I'd suggest you do it because you need your work inspected and signed off. After he leaves you can do what you want with the work.
Then some time after it's signed off, call the building official for that jurisdiction and explain that you were compelled to rework the job for reasons you believe are not required by code and that absent citing an Article in each rejection item, there is no reason to believe this inspector is going to change. It costs you money and makes you look bad with your customer. Going back and reworking your job because an inspector dreams something out of thin air is not good business practice for you, your client, or the building department. Citing a code section (or in the case of the NEC an Article) is good practice in every building department when rejecting plans or inspections. If you read the administrative chapter of the code or adopting statute, it probably compels the inspector to cite a code section in a rejection.
I always told my inspectors and plans examiners that if you can't find a code section, it's not a violation. And as for oddball situations, only a supervisor can make those calls (one that comes to mind was a chemistry lab in a college; I wanted two exits even though code then only required one so I cited the "extenuating circumstances" provision of the code in effect at the time.
There are two types of building officials. Those who have used tools and those who have not. The ones who have not can be real as*******es, they'll call you a liar and think you're out to cheat the world. The ones who have want to work with you and your customer to meet the minimum requirements of code which is in everyone's interest.