So I thought I would report back on a couple solutions to minimize the faceted terminator artifacts that appear on low poly assets using octane render in Unity.
The first solution is to use this free asset:https://assetstore.unity.com/packages/tools/modeling/catmull-clark-mesh-subdivision-95479
The above asset can be used to subdivide the meshes in your shot near the camera that might be causing shading issues. But even with 2 subdiv levels you still might have the dreaded terminator issues.
So the 2nd thing you'll need to do is increase the Ray epsilon in the PBR render target.
Using both these things together, you should be able to get production quality renders out of Octane Unity (for static assets at least).
My thoughts are that if this free asset can do what I asking, I think it's reasonable for Octane for Unity to be able to do this at render time. If meshes in the scene had an exposed property for subdiv level, that would be fantastic.
Also, .002 or .003 might be a better starting default for ray epsilon.