Type Selector filtering with PostRequestForElementTypePlacement

I am trying to create a ribbon button command for selecting a device of a certain BuiltInCategory and placing it using doc.PostRequestForElementTypePlacement(elementType).

It works, however the Type Selector in the properties palette seems to display all of the families I have loaded in. Is there any way to restrict or filter what gets displayed in the type selector? 

    class Communication : IExternalCommand
    {
        Application app;
        Document doc;
        public Result Execute(ExternalCommandData commandData, ref string message, ElementSet elements)
        {
            UIApplication uiApp = commandData.Application;
            UIDocument uiDoc = uiApp.ActiveUIDocument;
            app = uiApp.Application;
            doc = uiDoc.Document;

            FilteredElementCollector CommunicationsCollector = new FilteredElementCollector(doc);
            CommunicationsCollector.OfClass(typeof(FamilySymbol));
            CommunicationsCollector.OfCategory(BuiltInCategory.OST_CommunicationDevices);

            if (CommunicationsCollector.FirstElement() == null)
            {
                TaskDialog.Show("Electrical Devices", "No Communication Devices family is loaded in the project.");
                return Result.Cancelled;
            }

            ElementType elemType = CommunicationsCollector.FirstElement() as ElementType;
            uiDoc.PostRequestForElementTypePlacement(elemType);

            return Result.Succeeded;
        }
    }