Hey nutduster, getting back to you on this. I think it was object count. I deleted some rocks, some inclines, and a couple decoratives. Nothing that would have lagged the game due to being glass or lights. So that was really it. No lag from green room anymore seems to me like Halo 4 is only slightly better than Reach when it comes to frame rate lag. Which is sad, it's something we thought FOR SuRE would be fixed.
Ok, the same map I thought I had no FRL in when playing Single player, still doesn't... BUT, it does have FRL when playing in split-screen when looking at the central structure. It doesn't appear unplayable for split-screeners, but it's not without issue. The map is currently 8100/10000 in budget used.