Can you set the AVAudioSessionCategory to playback? Do I change it outside of the library or within the library

There’s no built-in mechanism for changing the audio session category inside the framework (in fact, it’s required by the framework that you let it set its own audio session settings for good results) but you can always make your own calls to the audio session using standard AVAudioSession methods in parts of your app which don’t need to actively use OpenEars classes.