I discovered neon just recently and it looks like a great plugin.
One thing I'm trying to figure out is interior shading. I only seem to get black ceilings in interior renders. Any Ideas?
THe issue is that light does not bounce, so only light that would hit the surface directly actually lights it. In all three of your example shots, the light source is above the roof that you are having issues with. The easiest solution is to set up a very slight ambient light level so no part of the scene is truly black.
Yes, here is what you should do:
Why does this work?