I have created a feature service layer, but would like to have some fields with default value. I have tried to use the "Update Definition" without success, getting the error "Invalid definition for 'SourceSchemaChangesAllowed'.
Invalid definition for System.Boolean.
I went further and defined some fields using the ArcGIS online, and the fields were assigned default values, however, when I use Geoform to upload some data, those fields do not have a default value as defined.
You can't updated default values after a field has been created. You can set default values for fields when publishing or when adding new fields to a web map.