bump
I really think this should be considered. TG2 doesn't have the range of material shaders, yet, to match the likes of Mental Ray. Landscape shaders are its strength. Until it does, I really believe the option to switch off object primary rays should be added (like most any other entity has the option) to create a clean background for comp and subtle FX, but object shadows and reflections (reflection as a subtle influence probably) are present.