Cubik StudioAs a working example, the user could use the Scale option to re-size their large model so that it can be broken up into 16x16x16 block segments which the user can then isolate and export as individual parts, so that the large model can be built up block by block in-game.
The Slice tool could then be used by selecting the tool, clicking in the model view, which creates a brightly-colored line to show the user what the slice will affect, and the user can click and drag the line over their large model (I would recommend enabling Snap on the slice tool so that it conforms to either a 0, 45, or 90 degree plane). Releasing the mouse would produce a small window asking the user to confirm their Slice selection. Pressing OK would apply the slice, cutting the Elements the slice line bisected in two. The slice can have a radio option in the upper portion of the program titled 'Contiguous'. Having this option checked would make the slice only affect the Elements that the slice tool bisected (ie: assume you have three rows containing three cubes per row; with Contiguous checked, if the user creates a horizontal slice through the second row of cubes from the North View, only those three cubes in the row closest to the northern view will be sliced in half). If Contiguous is unchecked, the slice would apply to every cube in the center row. See the below graph for a visual example:
