Hi Paul,
the Octane plugin is generating its materials from the Archicad Internal-Engine-Material settings now, isn't it?
Is there a plan to let him do this from The CineRender materials?
I'm not very familiar (unfortunately) with C4D itself but AFAIK the settings for this in Archicad are covering
all the settings that are natively in C4D material settings. And Archicad can also import materials from C4D now.
Perhaps you could even use the conversion method already used in C4D-plugin -> Octane?
Greetins,
Artur