The lighting for the office didn't take as long as I thought it would to sort out. I may actually (finally) be coming up with a decent system to light most of these indoor rooms. The original lighting was frankly quite ridiculous. There is a point light in the lamp, which I kept, and then there were like 10 point lights in the middle of the room for some reason. I didn't take a close look though, so they might have been a bunch of spot lamps all pointed in different directions in order to light the room.
The light level was fine, but all the shadows would have been as if the light was from the center of the room. Not to mention what would happen if you stood too close or in those lamps. What a terrible way to light a room! I really don't know what the creator was thinking when they did that. Maybe that's how the light it for the preview renders on their product page?
Anyway, I deleted all of that. I have used Mesh Lights for a long time in both Daz and Poser. I like the softer light they provide, and the control they provide. I have also used "invisible" mesh lights, where you make them completely transparent, so that you can't see the light, but they still provide their illumination to the scene.
Daz recently upgraded to version 4.2, and one of the changes they made was to transparent objects with emissive materials (i.e. invisible mesh lights). It used to be that if you made a "light" transparent, then it would still provide light but not as much. You didn't know how much less. It just changed the light. So you could guess at how much to make it brighter to get your lighting level back, but it was total guess work.
Now it's a linear progression. If you make the mesh light 10% transparent, then turn the brightness up 10%. 100% transparent, then make it 100% brighter for the exact same level of light. It's an exact match, and makes lighting with invisible mesh lights so much better and easier. :)