Because it's an interaction. It should use the interaction interface and not some self-made hack. Previously, setting down a carry heavy object would always be executed even if aborted with Space+S.
Library_Inventory: handles slots and an arbitrary amount of hands, generic and not only Clonk-related
Library_InventoryControl: interactions between the user and the inventory
Library_CarryHeavyControl: interaction with carry-heavy-objects
Library_ClonkGamepadControl: gamepad-related stuff
Library_ClonkControl: general Clonk control library