AAF is the native format
Because AAF is Avid's own, there is no lossy interchange step on the Avid side — the AAF imports as a sequence with its tracks, clips and metadata intact. fcp2aaf writes to the standard, so the Audio Channel Combiner setting stays off and every channel arrives on its own track.
Embedded or linked
An embedded AAF holds the audio inside a single file, which is the simplest thing to bring in. A referenced delivery is a folder with the AAF and the conformed WAVs beside it, under readable names, for a pipeline that would rather link than import media.
Roles as tracks, timecode for relinking
Each Final Cut role and subrole becomes its own track. The session start timecode is written in, and each recording carries the source timecode the machine stamped, so material can be matched back to the rushes.
You set the track order, the names and which tracks travel before converting, with the whole session drawn in front of you.
The audio edit, not the picture
fcp2aaf's AAF is an audio session. It carries the sound of the edit and where every piece of it falls. It does not carry the video — Media Composer's picture comes across by other routes, and that is not what this application does.
fcp2aaf does not pass audio through. It reads the paths Final Cut wrote into the FCPXML, opens your original recordings, and cuts from them exactly the regions the edit uses, with as much or as little handle around each clip as you ask for. WAV, BWF, RF64, AIFF, CAF, FLAC, MP3, MP4, MOV and MXF are read straight from the drive, at any size.