Convolver + ReplayGain

[AnnieBody]

I created 3x mp3 and 3 x flac files from one wav track. To these I manually added (using Mp3Tag) the replaygain trackgain of 0db, +12db and -12db so I had one of each gain per file type.

After much trial and error I have found the following settings partially work:
stream.transcode
dsf(>64):wav24;176, wav(>24;192):wav24;192, mp3:wav24, flac:wav24; [only the mp3 and flac settings relate to replaygain]
stream options
convOut=-i "C:\Internet\MinimServer\opt\bin\convolution\ORA10_HD650_Impulse.wav" -lavfi "afir=gtype=gn,volume=replaygain=track"

I say partially because the replaygain +12db doesn't appear to work.
If I play the files on my PC using foobar then the gain differences are clearly and unmistakingly audible.
But when I use MinimServer only the -12dB is applied, the other two tracks having the same volume.
So what is preventing the replaygain + setting from being utilised?