We had great success with this approach, on two different nights a couple weeks ago. (End of Jan, beginning of Feb)
Night 1 - it was pouring rain, and there was almost no one in line 15 minutes before park close. So we hopped in, walked straight through without stopping, rode and thought... Well, it's two minutes to close, let's see if we can get on again! And we did! The cast member closed the line right behind us, so we were the last ones on.
Night 2 - much more pleasant evening. 15 minutes before park close. The sign said 25 minutes, but we thought, "Eh, we're not in a hurry. Let's hop in." Not a walk-on, but still a short line. In less than 15 minutes, we were on our boat. We did not, however, make it out in time for a second ride.
So, I think this is definitely the way to go, when it comes to riding NRJ!