It's an ongoing problem. I have no frame issues throughout the whole game, but the second I enter the base while the lights are on there are massive drops. Luckily, I have a pretty good jury rigged solution that will work until the optimization patch arrives.
Buy Christmas lights. Turn off all the normal base lights, and string Christmas lights through the entire base. After I did this, my base was lit and all my framerate issues disappeared. As a bonus, the lights won't go out when there's a power outage.