As far as I can see, ckanext-geoview supports the visualization of resources of the format arcgis_rest. However, it seems that using an ArcGIS MapServer as the base layer for visualizing resources of other formats (e.g. a separate GeoJSON file) is currently not supported (according to the docs, supported are Stamen, MapBox and custom XYZ URLs).
As far as I can see, ckanext-geoview supports the visualization of resources of the format
arcgis_rest. However, it seems that using an ArcGIS MapServer as the base layer for visualizing resources of other formats (e.g. a separate GeoJSON file) is currently not supported (according to the docs, supported are Stamen, MapBox and custom XYZ URLs).