0.53b is live. Aside from the usual bunch of bug fixes, this also brings two new features. The first is individual rates (RC Rate/Superrate/RC expo) for Roll/Pitch/Yaw. Due to the number of rates, the 5-0 keys no longer are used to manipulate them. This is now done via a new Flight Assist Page (press A) This will also give you a way of easily editing the rates via a UI and several ways of visualising them.
The other major part of this release is Quad-Ball: The Game. Previously available in beta, we took on the feedback to make things more accessable to all.
Quad-Ball now has it's own menu, and it's own set of rates/camera setup so there's no need to alter your regular setup. The game also supports Steam Leaderboards - in the future they'll be in the game, but for now you can see how you are doing compared to everyone else here https://steamcommunity.com/stats/1331330/leaderboards/6235874
More explanation of the features are in the wiki, and also this YouTube video
https://www.youtube.com/watch?v=LuZ_jtVEiF4