Non-exclusive export route

In the same way that import routes have "Accept assigned only", export routes should have "Supply assigned only". This way a storage building can for example still be used by trucks in the same logistics zone, even though the storage building supplies a storage building in another zone.

This would be very useful for Fuel Stations. I often want one of my fuel stations to supply a specific mining tower as well as free roaming tree harvesters in the area. However if I set it to supply the tower, I think it only supplies the tower and the tree harvesters have to get their fuel from somewhere else.
If there was an "Supply assigned only" on the fuel station, I would be able to uncheck that and make the fuel station supply the tree harvesters as well. (However the mining tower would "Accept assigned only", which would prevent refueling trucks from driving across the map to refuel the excavators.