We have considered adding OpenEXR support to the QubeGUI. The way to do it right now is to use an external viewer and tie it in with the QubeGUI under the Preferences dialog. That will allow you to display OpenEXR images with the output displayed from Qube with all of the controls of a full EXR viewer.
At this time, since it requires including additional libraries (for each platform that we support) and there is an alternate workflow, the work has been deferred. We may revisit it in the future.
