Hi,
does 'Use peak info to scale down tracks that still clip...' do strictly what it says (look only at the track_peak values) or does it work for entire albums when the replaygain mode is set to album gain (look at album_peak and album_gain and scale down all tracks by the same amount if necessary)?
Thanks.

Figured it out myself. When replaygain is set to album mode, album_peak is used to scale down all the tracks by the same amount, preserving differences in loudness between them.
Nice talking to myself.