Datum transformation are not applied to multipatch features using the Project Tool in ArcToolBox.
If a datum transformation is applied in ArcMap, the transformation works in the reverse direction but does not work in the forward direction.
Additional data: The shapefile is projected from Germany Zone 3 on DHDN to ETRS_1989_UTM_Zone_32N using the transformation DHDN_To_ETRS_1989_2. The output multipatch features are in the wrong location when displayed in ArcMap if the forward transformation is applied. The transformation works correctly if the reverse transformation is applied. The datum transformation has not been performed on the multipatch features in the feature class mp1gk3.shp.