I'm also seeing a discrepency in the miners' priorities- by default, picking up ore is the lowest priority.
However in larger maps when I end up having a whole lot of rubble around and I want to build something, I have to wait a long time to get it done because everyone is too busy picking up ore across the map (let alone the ore in immediate visibility to the base, LET ALONE the mountains of rubble I still have all over the place, or any orders to dig or reinforce walls, which are usually at the top of the priorities list) to bother putting any of the collected ore or studs into the structure right next to the tool shed.
I have to either manually control a miner to deposit the ore into the new structure, or completely disable ore pickup in the priority list.