@AmigaFuture
I think I found where I saw how to do it.
The new version of BD_RB has an option for intact video and intact audio. Look in the Alternate text file. You might have to create your own alternate profile.
Code:
[0000x]
caption=MKV Intact video and audio
vBitrate=2000
aBitrate=0
aType=2
vFormat=8
cType=1