I apologize, I was under the impression that DisplayLabel was an existing WPF control, when it appears to be a custom control for the application. As a result, I don't expect Test Studio to be able to add it. It appears to be some kind of modified TextBox, as seen in DOM:
The primary problem is that the Text property is not consistently accessible. If the element is located in the DOM and added to the Element Library, it can be accessed in code - Applications.MyApp.MyWindow.DisplayLabel1.Text will return the string of content as expected. However, for any sort of dynamic finding, such as Applications.MyApp.MyWindow.Find.ByExpression(new XamlFindExpression("XamlTag=DisplayLabel")), the element will be found correctly, but accessing the .Text property results in an empty string. This occurs no matter what dynamic find logic is used - XamlPath, indexing through .Children, Find.ByTextContent(), etc.
Here is a DOM snippet, with a DisplayLabel highlighted:
The ItemsControl at the top is easy to find using the name. The StackPanel contains multiple (the exact number may vary) ContentPresenters, all of which are structured the same way. I'd like to be able to loop through them, find the DisplayLabel, and get its text for validation purposes.