I have a case where I cant edit the existing code for a content type, so I am adding properties programmatically. Since there is no code, is there a way to use the UIHint feature to specify features like SelectionOne or SelectMany on a property to show a dropdown?
Not sure if I understand your question correctly.
You are creating properties using code, correct?
If so why not just use a selection factory to populate the dropdown and then apply a selectmany or selectone attribute?