You weren’t the one who resurrected it and I think it was appropriate that you closed it out again with accurate information for the next person who stumbles across it.
The dataplate tells you a #10 is sufficient and you still question and say you are erroring on the side of caution? The specialist, the manufacturer, already said the #10 is correct. All you are doing is costing someone money to refute something that should never have been written up and giving a negative impression of your industry.