Well delivery and destination is kind of the same, isn't it? I mean in both cases you can use the street if your start or end is on that street, but not otherwise (from the perspective of the router, at least)I can't find something about motor_vehicle=delivery in your link. I've just found something about motor_vehicle=destination. And this is solved.
I don't think it is solved. Look at what happens if I put the start or the end inside the "delivery" zone:
And I think, the problem with motor_vehicle=delivery is also solved in osrm... Have a look at my postet link: http://map.project-osrm.org/?z=15¢er=46.895349%2C7.491045&loc=46.887827%2C7.496345&loc=46.881154%2C7.482033&hl=en&alt=0
There its routing correct. Its just in routing.osm.ch where its wrong.