Occulusion Culling with render textures

Is there a way to make unity’s occulusion culling system play well with render textures? I have heard that occulusion culling decides what to render based on only the camera marked as Main. Can one add the cameras used for render textures into the occulusion system so the objects rendered by these cameras will be taken into account as well as the main camera when deciding what to render?

No one knows?