so as silly as it sounds but would adding more fuel help to lower the preignition of petrol by trying to keep the combution chamber cooler,
Yes but not for that reason, a rich mixture is hard to ignite than a lean on lambda 1 mixture, so race set ups especially in the old days of carbs instead of injection and management always erred on the rich side as a safety margin to prevent detonation or pinking.
No I haven't been cutting and pasting either, just been around a lot of competition motors, engine builders etc over the years.