Here we are in 2019, and still no easy way to separate multiple channel audio…
I downloaded a demo of Nuendo and separate tracks there. I can also join split stereo without having to convert, as it just links them. Super smart, and wish that was a feature available in Cubase.
Just as an aside… convert stereo to mono merges L & R… no good for dialog editing where a stereo capture of a mono source results in audio on one side, and noise on the other. Files need to be SPLIT, not converted to mono.