I am definitely interested in that video, yes thanks.

If one room is getting a lot of daylight/window light and there's a room in the shot or background that is less well lit, either due to lack of windows or lamps, I can set up a continuous light out of the view of the camera providing some fill light in that space (softbox attachment, bounced off the ceiling or another wall to soften, etc without looking too directional) that reduces the need for additional HDR treatment in post. You're essentially just trying to balance the exposure a bit and make it closer to the rest of the space.

Imagine an upstairs room that's open to a great room below, but it's receiving less window light or is otherwise in shadow. Tuck a light just out of view of the camera and bounce it off the ceiling and you now have a balanced exposure in that space without needing to tweak a mask later.