Box height calculation incorrect when using cap lids

[jmickelin]

I created the following box:

        [
            [ BOX_SIZE_XYZ, [150, 233, 40.6] ], 
            [ BOX_STACKABLE_B, f],

            [ BOX_LID,
                [
                    [ LID_SOLID_B, t ],
                    [ LID_INSET_B, f ],
                    [ LID_FIT_UNDER_B, f ],
                    [ LID_HEIGHT, lid_height ],
                ]
            ],                 
        ]

Expected behavior: According to the documentation, the exterior dimensions of the resulting box should be 150mm x 233mm x 40.6mm. I interpret this to mean that the height of the bottom half of the box should is adjusted so that the entire box ends up being exactly 40.6mm when the lid is attached.

Actual behavior: The bottom half of the box alone ends up being 40.6mm in height, so the total height of the box is incorrect (measured height after printing ends up being 42.44mm).