I think there's only a handful of us that use the ASX duplicate file substitution so I'm not holding my breath on this wish, but I'll put it out there anyway
I understand why ASX files don't normally have replaygain tags (as they are normally links to streaming files)
but in relation to there use as library redirection files it would be great to be able to manually write them.
Currently MB draws the from the original file.
This is OK for the track gain and peak.
But if you run 'Analyse Volume' before the substitution, then you can see that the album gain and peak can differ considerably.
So if you TLDR the above;
<param name = "replaygain_album_gain" value = "-8.62 dB" />
<param name = "replaygain_album_peak" value = "1.050584" />
if that exists in the MB redirection file, MB uses these values, otherwise it just does what it currently does.