I •••Spoiler: Sacrificed all three girls and nothing happened, so I guess there is no extra scene.
Also, here are some tips for the vortex.
•••Spoiler: Take nine boosts, of course. There's not really any walls to hit in the vortex, so you can easily save yourself from bad jumps nine times.
In the vortex, for some reason, you don't really have to land on top of things to reset your jump meter. Usually hitting them on the side will do. So realize the rules are different and don't give up just because you didn't perfectly land a jump.
Also, you usually pass a bit into anything you hit on the side and that helps.