Cannot start Nexus 9 screen mirroring to Viera TV
Managed to do it thanks to this: after adding persist.debug.wfd.enable=1 to build.prop the option to enable wireless display appeared in cast screen options. It took several attempts to connect and I don't really know what did it work after all, but it works now.

One drawback remains though - when mirroring display I don't have access to the wireless router, so I cannot display any new content from, say, facebook, only the stuff that was cached beforehand. But this is obviously the matter of a different question.