My understanding of how people tend to use the master volume is that they set it to the max volume they want the club sound-system to be at. So making the bypass gain skip the master volume could potentially play the bypass channel at a higher-than-max volume -- which would be undesired on the user's part. Thoughts?

I see that you combine the master volume with the compressor gain -- instead, you could provide the compressor gain as an additional argument to setGains or you could pre-multiply it with the orientation gains?