It's possible to export/teleport products from the Ore sorting plant (to the nearest storage) for free by unassigning/re-assigning the product to the Ore sorting plant.
Whether this is an oversight or a design choice, it's possible to exploit this mechanic to both unclog the ore sorting plant from rock, dirt, or other unwanted products, as well as rapidly teleporting coal, ores, etc. to storages, technically eliminating the need for trucks or belts to take the products back to the factory. It could be considered a cheat when considering achievements.
I would suggest this is fixed by maintaining the inventory of products in the ore sorter regardless of product assignments, offering the player to empty the hidden inventory using Unity. This would be consistent with building inventory mechanics in general.
