CubeMagic engine calculates the optimal arrangement with many parameters etc. a settlement of volume efficiency or collecting a cargo of the same kind, vertical setting or horizontal setting. However, there is no perfect answer perfect on such an optimization problem, and a part of calculation result by engine is changed by your needs.
CubeMagic prepares the following flexible edit functions, and can change arrangement visually.
New kind cargo cannot be added with the CubeMagic.
When you add a new kind cargo, you adds a new kind cargo by the CubeMagic packing editor
and CubeMagic engine calculates arrangement, look at it with a CubeMagic.