[opus] R128Gain question

[Alice Wonder]

Just a quick question to make sure my understanding is correct on something.

R128Gain is part of the opus standard and the information is part of the 
stream itself, correct?

So if I use mkvmerge to take an opus stream from an ogg opus source and 
stick it into a Matroska audio, I don't have to worry about replaygain 
or r128gain tags because the opus stream itself will have the gain 
information needed by an opus compliant decoder.

Is this assumption correct?

My particular scenario doesn't need to worry about album gain.