@Noughty, ok so long as you intentionally are overwriting that is fine, I just wanted to make sure you realised you didn't have to. Personally I rarely have title and author overwriting turned on as I already have the book title & author that I want but I understand that if you working from ISBN then you do want that function.
My original comments on this request stand - it requires primarily changes to Calibre and is not something that can be done in a standalone plugin without restricting how you add books to Calibre.
https://www.mobileread.com/forums/sho...&postcount=150