You can contact the Okular team in many ways.
We have a mailing list to coordinate the Okular development. The mailing list
and hosted at kde.org.
You can use it to talk about the development of the core application, but also feedback about existent or new backends is appreciated.
Bugs and Wishes
Bugs and Wishes should be reported to the KDE bug tracker at http://bugs.kde.org.
[ Edit ]