They didn't ask you to inspect the property in your scope of work. The asked you to inspect specific repair items, which is not an appraisal. However, this is why most of us don't do other appraiser's repair list. Personally, I would tell the lender to use another appraiser, no charge for my report. Is that better than losing this lender at this point in time of being dead.
We're talking about how much of a fee to do this argument and lose the client. Stop thinking like i'm totally right, and you the client must obey me. They can always get someone else and not pay you anyway. This is not the hill to die on, it's a bump.