Just forget that separate lot, the agreement has been amended, it's gone. Lenders and owners don't know this excess/surplus land use nonsense. So the lender now won't put a lien on it, they don't need it. If the lender, or seller, knew this nonsense originally they would have left it off. The owner didn't know, thought they probable had to make it a non removable part of the house sale. It is a separate removable lot. Forget the highest and best use, it should have never been part of the original appraisal.
He did the appraisal as if the extra lot wasn't part of, It didn't affect anything but the agreement of sale, now it's official gone. This thread should now be official gone with some of these posts. Of course you can just put a new inspection date with a new picture of the front of the house with a new file number if you want to. That's your business decision. But as far as surplus/excess, you did it the right way the first time.