Pathing requirement difficulty option for Quick deliver

The difficulty of the most challenging 'You Shall Not Pass' map can be made trivial by using quick deliver to build a Vehicles Depot and vehicles on the upper plateau. This instantly gives access to all required resources on the upper plateau except oil and ocean dumping, which can also be accessed by building pipes snaking down the side of the valley (and building resources for these can also be quick delivered if required).
This exploit could be mitigated by putting in a difficulty option that requires a path between stored resources used by quick deliver, and the building being quick delivered to. The requirements on the pathing could be more lenient than for vehicles, to recognise Unity being used and people being able to move in places that vehicles can't, but would prevent quick deliver being used to build in completely inaccessible places.