I'd like to see more functionality for the 3D intersection tool, which currently is available only for multipatches.
It could be useful to be able to intersect two 3D polygons, which would output a 3D line.
Additionally, I'd like to be able to intersect a 3D vector polygon with a raster such as a DEM. This could have applications with geologic data, like intersecting a 3D polygon representing a fault plane or a stratigraphic surface with a DEM representing the topographic surface to obtain a 3D line. This line would represent a fault or contact where it is exposed at the surface.