You can run your files through ffmpeg and remux them to have the audio in external files.
No and yes.
No, this option would be useful because not everyone knows how to use ffmpeg.
Yes, I already made my script (between my first post and now)
ffmpeg -y -i "%OBS%\%VIDEO%.mp4" -map 0:2 -vn -c:a copy "%OBS%\%VIDEO%_2.aac"
This cmd extracts only the audio track 2, because in 50000kbs 60fps, the video makes several Giga (and some session goes up to 50G) video extraction it is a bit long (so we come back on No).
In short, I'm getting out of this problem, was for others that I think. This option could be useful for newcomers (and other recorder software on this option), so kept this idea whatever pars.
In any case, thank you for answering.