{wf}shadowspawn
I mapped while q3 was open, and as I was clipping through the map, I just created func_groups on the brushes that had sunlight hitting them. I used a func_group with lightmapscale .1

pic below is that func_group with _lightmapscale .1 ( -super 3 )

the top one is -thresh .5 -super 3

below is just a filter with defaults, & -thresh .5 super 5