Those methods were for desktop mode, not a web. you need to remember this is a framework for dual UI mode.
UniGUI is a fresh one, it's not a mature framework yet. This is its first step so you need to manage some action your-self.
By the way, your question is a good idea. By a "Asynchronous" nature it is possible that every UniGUI component's methods can parallel send and receive ajax-request itself, but that needs more design and take more time to implement. Implement more web UI supported by ExtJS should be the first priority, IMO.