Since ArcGIS Pro 2.2 and QGIS 3.2 arrived recently, it was time to have again a look if and how the AT_GIS_GRID for CRS-transformation between Austrian BMN (Bundesmeldenetz) and ETRS89 (and WGS84) is implemented. The easy question: Does EPSG::5891 (AT_GIS_GRID NTv2 transformation) work out of the box ?