PS. For me it would be logical if the following logic would be followed:
first look if the album replaygain is present. If so, use it; if not, look
if track replaygain is present. If so, use it; if not, don't apply
replaygain.
I don't see why album replaygain has precedence over track replaygain, i think track replaygain has precedence over album replaygain... it is specific to that track, if not present there use album replaygain.
Just an opinion
santiago