Everything worked great. I had an actual hard deadline for a VFX shot with a volume in it, and Octane really saved the day. I'll share some details about the various workarounds I had to do to render my relatively simple VFX scene.
I used the Maya plugin to export an .orbx to use in Standalone 3. I had to uncheck the merge all objects into one alembic scene option in order to get the camera animation to be recognized in Octane Standalone, which isn't documented anywhere. Perhaps you should add a section called, "Animation," to your manual, and include this detail.
Naturally a volume primitive or transform did not export from Maya, so I had to manually place my volume into the scene. Fortunately its transform did not animate, but it did have a transform. Bug: A volume basically vanishes when you reduce its scale in Octane Standalone. To address this, I transformed the entire scene such that the volume's transform was (0,0,0) (0,0,0) (1,1,1). I did this by parenting the scene to the volume in Maya, changing (not resetting) the transform of the volume to (0,0,0) (0,0,0) (1,1,1) and unparenting everything. You may need to parent the camera to a curve / locator to keep its animation curves correct. Since FumeFX treats the pivot point of its fluid container in the lower left corner, I placed my volume with a Placer node at (-width/2, -height/2, -depth/2) (0,0,0) (1,1,1). This resulted in the right composition.
My kernel settings seemed to have no effect on the quality of the volume. Note, I did not use any emission from the volume and just texture lighting.
I could not set the velocity and hence have no motion blur in my volume. Like other posters have mentioned, it would be great to specify how to interpret the 3 "Velocity" channels in FumeFX as a single vec3 velocity.
Windows 10 with Maya 2016