Tony on our team send me an in-progress version of his UIXViewController project that adds an ADF UIX view layer for the ADF Toy Store demo. We're triaging a couple of issues with it.
The first one related to the fact that ADF UIX does not require the Struts form bean. It works directly with the ADF bindings. What's more, since the presence of a Struts form bean causes trouble for the ADF UIX file upload functionality, at least in 18.104.22.168 and 22.214.171.124 the StrutsUixPageLifecycle ends up short-circuiting the form bean altogether. Tony was hitting a NullPointerException in my SigninAction because that class was depending on pulling the username and password from a custom LoginForm action form.
To resolve the problem, I've switched implementation techniques (in the in-progress version we're working on) for the login page, creating a simple LoginBean javabean that is not a Struts action form, and creating a DataControl for this simple bean. Then, I changed the SigninAction class to pull the username and password from this LoginBean in the model layer. ADF Bindings handles the data binding to these simple beans too, so it was only a minor change.