Fuel Station toggle: Deliver to Assigned Only

If you have no fuel stations, excavators and tree harvesters will travel to the closest source of fuel to refuel. As soon as you build a single fuel station, they all stop doing this, no matter how much closer the nearest source of fuel is than the fuel station.
I'd like to have a toggle on the Fuel Station that causes its assigned trucks to **only** service the towers it's assigned to (advanced logistic export route), **and** (this is important) to have excavators continue to get their own fuel if there's no Fuel Station that can service them.

That is a thing (Allow any vehicle to refuel here) turn that of