Please allow the option to choose the default symbol (InfoWater Model Preferences) and Map Display symbol from the "Styles" built into ArcGIS Pro. Both ESRI and my company have custom .stylx files that house our custom symbols for points, polylines, and polygons. Having the option to chose the default style from these pre-populated styles would be fantastic. Currently, the options to change the symbol feel like it limits the modeler to changing either the color or the size.

To see where these styles live in ArcGIS Pro, head to the View tab, click on Catalog Pane, then drop down the Styles section. You should see "ArcGIS 2D" "ArcGIS 3D", and "ArcGIS Colors" which are the default templates.