Ive been working on the seriously untouched brightmaps lump, Ive pretty much got everything in Doom, Heretic and Hexen complete, it isnt perfect, there may be a few errors Ive not seen but yeah, I've even done nearly textures that had lights, theres just a few Hexen sprites (such as torches) that I havnt done....
This will definitely need some work to see which ones can be added without negative side effects. For example, having some of the light textures bright won't work well because they are also often used as switched off versions of the lights.