Here's what I've set up.

What's missing?
I looked for Deep rendering in the manual, but it's only mentioned once, in a heading.
What does that even mean? I don't have any deep channel kernel.There are four major rendering kernels in OctaneRender™: Direct Lighting, Path Tracing, PMC and Deep Channel.
When I load the EXR in Nuke, I'm told this, which to me indicates the deep rendering in Octane isn't working properly, or I missed something.

What's also tipping me off is what the Shuffle node looks like.
I'm not a seasoned compositor, but I've never seen this before.

RGB isn't.. RGB. r R gG ?
Some input on the matter would be very helpful.