I'm confused by the OP in that he mentions he revised his report ( which would require a signature date change) then in his NOTE: at the bottom of the OP, he states nothing was changed in the original report.
If you pointed out to the reviewer that the report mentions no health and safety concerns in the Improvements section, then you can hold your ground. But it sounds as if the reviewer specifically wants the converted patio mentioned as no health and safety concerns.
So you've got to ask yourself, is this the hill you want to die on?
State in the report there are no health and safety concerns with the converted patio to living area, make note of it in the addendum, change the signature date and be done with it.