Yes, there a few things we're working on. First, we will improve the loading speed of some heavy pages in UNA in general, such as pages with Feeds (homepage especially), potentially using asynchronous loading of data items and other tricks. The apps will also change behaviour a bit to improve perceived speed and eventually work with more ReactJS elements to give that "instant reaction" feel of purely native apps.
Note that most of the speed issues come from the website itself. It's not possible to create a universal fully native app for UNA-based sites, because you can build very unique setups and the app would have to natively mimic that. Instead, we only define the most likely common elements (launch bar, authentication, search, notifications etc) for native components and rely on webview for the rest. Therefore any speed optimisations should first be done with the site in general. Apps just make this more urgent. :)