Is there any documentation or sample code I can review which provides an explanation of extending the UserForm widget. I want to capture the data that is submitted from the UserForm to allow me to do some additional processing on submit.
No documentation yet on the module. There are no hooks in the processing function (yet) so it's a bit tricky to extend it to do what you want. Most people currently subclass the UserDefinedForm class (and the Controller) and override the process function.