Further to this found where an issue originates in the /umbraco/Views/content/edit.html the line:

<umb-property property="property" ng-repeat="property in tab.properties">

doesn't have the properties in sorted order first. In fact when the property data is loaded the sort order for properties is ignored completely hence the properties will not load in the provided order but rather an arbitrary order will no opportunity to correct it in the controller Umbraco.Editors.Content.EditController. This is quite disturbing as I cannot find an angular resource which can provide the property type data to correct & sort the loaded properties by the sort order. Please can anyone suggest one? I am leaning towards an ugly custom edit to fix this. Ugly in that it would not be future proof for later Umbraco versions and would need to be stored outside & override the Umbraco edit view. That ugly.

Essentially the workaround would create a new custom UmbracoAuthorizedJsonController with the methods:

public List<PropertyType> GetPropertyTypesForNode(String id)
      {

          var helper = new UmbracoHelper(UmbracoContext.Current);
          var list = new List<PropertyType>();
          var result = 0;
          if (!String.IsNullOrWhiteSpace(id) && Int32.TryParse(id,out result))
          {
              var content = helper.TypedContent(result);
              if (content != null)
              {
                  list.AddRange(GetContentTypePropertyTypes(content.DocumentTypeId));
              }

          }

          return list;
      }

      private List<PropertyType> GetContentTypePropertyTypes(int id)
      {

          var list = new List<PropertyType>();
          var doctype = UmbracoContext.Application.Services.ContentTypeService.GetContentType(id);
          if (doctype != null)
          {
              list = doctype.PropertyTypes.ToList();
              if (doctype.ParentId != 0)
              {
                  list.AddRange(GetContentTypePropertyTypes(doctype.ParentId));
              }
          }

          return list;
      } 

Then create a new plugin manifest which will include: 1. a resource to call the controller methods

angular.module("umbraco.resources").factory("propertyTypeResource", function ($q, $http) {
    return {
        getPropertyTypesForNode: function (id) {
           return $http.get("Backoffice/ApiExtensions/DocumentPropertyTypes/GetPropertyTypesForNode?id=" + id);
        },
    };

});

and 2. a copy of the Umbraco.Editors.Content.EditController renamed with an additional code block added to the end of the init(content) function:

propertyTypeResource.getPropertyTypesForNode($scope.content.id).then(function(response) {
            _.each(response.data, function(e, i) {
                _.each($scope.content.tabs, function(tab, j) {
                    _.each(tab.properties, function(prop, k) {
                        if (prop != undefined && prop.alias != undefined && e !=undefined && e.Alias!=undefined && prop.alias==e.Alias) {
                            prop.sortOrder = e.SortOrder;
                        }
                    });
                });
            });
        }, function (error) { });

Then change the edit.html to use the new copied controller instead and add a orderby clause to the ng-repeat of properties:

<umb-property property="property" ng-repeat="property in tab.properties | orderBy:'+sortOrder'">

Now the ng-repeat will order the properties by the sortOrder they had been provided in the doctype definition (stored in db) and will correctly sort parent child properties. However this would be a specific change across the edit.html and will need to be checked/perhaps reedited when updating Umbraco (hence not future proof).