Empty Distance Object Field makes it use self

Hello, When using the distance expression in drivers, I noticed that you have to select 2 objects to get the distance. This means that copying drivers would always have the same objects they take the distance from. So my idea is, when you leave one of the two fields empty, it does not show an error, instead it uses the object that has the driver as the object it takes the distance from. This would allow copying drivers between objects without wasting a lot of time on redoing a driver everytime on a different objects. This is not an issue on small scenes, but I usually have massive Landscapes where i use the distance to have a LOD calculation and there it is quite tideouse to fix it for thousends of objects.