My knowledge is through experimenting mostly so take it for what it is. Generally though only a few parts really need to be lubricated, in Prontor/Compur shutters the escapement mechanism can do with some oil but only in minute amounts: a droplet is huge in comparison, I apply the oil with the top of a sewing needle, very tiny amounts and only at the bearings of the axles. Grease is more for gliding areas and against corrosion on larger springs. If any oil manages to get to the shutter blades (oil can creep slowly to them...) they will slow down or stick altogether even in room temperature.