Okay, so I can edit the scripts and create a new DSA file which will add in an IBL. That's not a problem. However, the issue comes when adding a sun light to the scene. The sun effectively overpowers the IBL, killing everything from reflections to the background. The Reality 'Sun' comes with its own sky model, and the only way to achieve the results I'm aiming for would be to set the gain of the sky to zero and beef up the IBL's in response.

Doing this programatically, however, seems to be a touch more difficult than that.

In my presets, the environment map effectively replaces the default sky you'd normally add with a sun. The result is very nice reflections with more accurate shadows. I'm sure there's a way to mimic this with Reality, so further advice would be helpful.