[FFmpeg-user] Default audio stream -- how do I set it?

[Mark Filipak]

I originally had a video with
0:0 = video
0:1 = commentary
0:2 = dialog
0:3 =subtitles

Of course, the commentary was the default audio.
I wanted to switch 0:1 & 0:2

ffmpeg -i SOURCE -map 0:0 -map 0:2 -map 0:1 -map 0:3 -codec copy TARGET

That succeeded...
0:0 = video
0:1 = dialog
0:2 = commentary
0:3 =subtitles

...except for 1 thing: The default audio is still the commentary (now
0:2). For several hours I searched and tried various methods to make
the new 0:1 the default, and failed.

How can I do it? ...Thanks!