I don't understand why the shape and fluid loaders have three levels, it looks like they only use one of the levels to load items. When the bottom level is overloaded, it doesn't load items in the middle level, and if a new shape or fluid is added, the bottom level is replaced with the new item instead of adding the new items to the middle level.
Problem is depicted on this gif:
Left most loader switches between red and green fluid, and the other two loaders can only load items on the bottom level insted of using the rest of the levels.
So I don't understand the point of having this three levels. Is it for storing more of the same item? or is it to have three different items stored? How can I take advantage of these three levels?