I
personally, WANT my oil to get good and hot, ALL of the time, (as the Ravenol FULL synthetic base stock oil I use can handle very high temps without breaking down/thinning out appreciably), since I want all of the moisture and fuel to be 'volitized' or boiled out of it every start cycle.
A better radiator will help keep it cooler anyway since the factory coolant to oil heat exchanger will become much more efficient with the improved cooling capacity of the aftermarket radiator.
Now yes, IF I were open tracking the car, for
extended sessions in the deep south/desert southwest, I would then consider an aftermarket, air-to-oil cooler.