wallpainter, the lighting model in DP isn't dynamic, it is a static lightmap pre-calculated by the RAD compiler.
Your idea wouldn't work because by default entities don't affect the lighting of a map, and that the lighting of a room isn't dynamically calculated.
If it was supported in Q2, why was it removed for DP? I mean, it has questionable gameplay implications, but I imagine it might add some novelty to some maps.
- Dagless