Hi,
Corona Slicer does not know how to "handle" the IDs, at they are coming from the slicing objects and not from the sliced object.
In the very example you posted, it is more like displacing the geometry. In such case, a Decal affecting only the displacement of the object will work exactly as you want. The issue is that it may be hard to "get" this displacement texture. Again, for the very example you posted, it can be relatively easy with using simple uv mapping and/or projection modifier, but of course to have it work with slicer will be better. This can be considered as a feature request indeed.