It would be nice to have the ability to add cased line symbols for polyline feature services. I know this can be accomplished by defining symbology when the map service layer is created but that approach is somewhat limited as symbology has to be the same for every map. ArcGIS Online and Portal offer very limited symbology options for polyline layers. It would be great if ESRI would build out its symbol library for polyline and polygon services. I know complex geometries are rendered best with simple symbols but there are a lot of use cases for cased symbols.