Once again, I yet fail to see how this "thrown forward effect" at MECO should be realistic. In my mind, the requested effect of the OP is nothing but a movie effect. Not that there is something wrong with that, but just to clarify.
Can somebody enlighten me, which force actually will kick the astronauts forward at MECO? I shall stand corrected if my ideas about this are wrong.
I think the scene in Apollo 13 for example was totally exaggerated. The astronauts are thrown forward into their straps and are pressed forward "hanging in there" almost helplessly, however, this implies that the booster was decelerating with at least 1G right after engine cut-off of the S-1C stage and before ignition of the second stage. I seriously doubt that. The only thing that could cause a slight jolt forward would be the back-pressure of the seat backs (having been under tension during acceleration). And that and only that may apply to the Shuttle seats as well.
Perhaps not the best example, but watch
getting flung off a carrier deck. The forward acceleration is around 3G's during the cat-shot, yet after leaving the deck, the pilots body or head are far from being nudged or even kicked forward.
Better yet: Watch this video, at 10:22 minutes you will see how
much the astronauts are thrown forward during MECO! Not at all.