sorry to resurrect and old thread, but I found this via a quick search on the net to see what's out there for alternate matte painting techniques. The superbrights element caught my attention and I've read your blog post metalrahul as well as this thread, and I want to be sure I'm not missing something.
In an attempt to get a handle on what it was you were dealing with, I rendered a 32 bit image from maya of just a ball and plane lit with a bright light. The resulting EXR I took to photoshop and applied an exposure adjustment layer, I lowered the exposure to see the information in the white area.. ie your superbrights. As I was working in 32bit, i selected an RGB value of 2 to have the super brights. set to low opacity and began to paint in new unique super brights..
so my question is, is there a downside to this? Since the adjustment layer doesn't affect the 32bit image since it's a non destructive edit, and you can turn it on and off as you work so you can see the end result.. it appears to save fine. Haven't taken it to Nuke yet to confirm, but I'll assume it works for now.
So, yeah I'm not sure if I missed the point or not.. It actually didn't really occur to me to work this way, until reading this thread :)
oh.. and I'm using CS4 to do this..
thanks in advance :)