I didn't see any method to allow this. You are already aware that you could use Microsoft's standard TreeView control. Is there a better way? That depends upon your definition of "better". I personally would not want regular users to see any "Test" elements, be it in my custom WinForm app or in PSE. Thus, I find it "better" to have an AFDatabase that has no references to "Test", in which case I could use the AFTreeView control. Off on a test system, I would have a restricted database that would include "Test" elements.
The term test in this case is misleading – it refers to manually entered lab tests, not things I am experimenting with. In a future release of the SDK, perhaps a “visible” property could be added to the AFElements an dby extension to the AFTreeView?
I will work on doing this with a standard TreeView built on the fly by parsing the AF database… This approach was actually what I had intended to do originally as I am new to AF, but after playing with the SDK a bit, I thought that the AF controls looked like they would do what I wanted.