How does this work? The programmer(s) are not tying inventory to a unique instance of the object holding them, if you place two objects overlapping, the game can't tell which of the two objects owns the inventory, if you remove one of the objects it'll return the inventory, but the remaining object still holds the original inventory. By the numbers: place a portable refiner Process stuff, for example runaway mold into nanites. DO NOT REMOVE the nanites. Click on the nanites and put them back in the output. place a nutrient processor. move the nutrient processor so it overlaps the portable refiner. check the nutrient processor inventory, you will see whatever was left on the input of the portable refiner, and whatever is on the output of the refiner. Both will be grayed out. delete the nutrient processor. your inventory now has the original contents of the portable refiner input and output. repeat. Don't forget step 3!