Offizieller Kommentar
@David > @Marek is correct; you can use the XDJ-RX as a "computer-free" experience, but your mobile device would be the unit doing the grunt-work of analysing your music and acting as the source when you want to play. There is no "export" when using rekordbox mobile, the audio files are imported to the app, then you connect your device and play from that device as the source.