The v12 etype isn’t really known for overheating. There is a design flaw in that only one cylinder head has a temperature sensor. I’d drill and tap the left hand front water housing for a second sender and use a spare wire to take the reading into the cabin where you can display it.
A ;little additional cooling can be had by engaging the heater matrix. This flow does bypass the radiator however.
Solving heatsoak - a worked example shows how radiator water temperature, ambient airflow from the fan post shutdown and cylinder head cooling are related by the circulation of hot water.
kind regards
Marek