The lots don’t exactly close. I think they stop charging for parking an hour or two before that park closes and bus transport to and from that park continues for about 90 minutes to 2 hours after that park closes. However, if you are thinking about dining at one of the Boardwalk area restaurants, I would park where you’re eating and then take transport to your park. Just make sure you have a reservation because sometimes the gatehouse guard will check. Additionally, if you have a TIW membership and are dining at that resort, you can valet for free (except of course your tip).
If you do park at the Studios and walk back to the Studios’ lot after dinner, you won’t be stopped and the path is well lit. Just keep in mind that once you get to the Studios, the tram will most likely not be running 90 minutes after park close and you could have a long walk to your car.