As mentionned, it's a performance / direction. So every intensity has more or less the same pace for each sample. there are some little exceptions, but this would lead to a problem making the choice of samples available very small, which is not gonna be good either. On top of that, for performances, I'd have to look up everytime the pause change at every sample, and find the shortest one. Which is not ideal with the amount of samples.
I'm treating this as a voice acting performance and allowing a bit of control, but just like in any porn scene where you'd like the voice of actor/tress X or Y, it's because of the voice and pace. If you'd want something different, you don't play the scene twice as fast, you either find another scene, or you need the director to "direct" the performance
In VAM's terms, find another scene is "change the voice" since the "direction" is static and chosen by me.
I'll make a final update soon to allow a negative pause just for you, because you're very kind and invested in making VAMM better and it's quite a very fast fix (and fix an annoying bug too) soon.
But after that I'm done. VAMM is never gonna be updated and I'll stop answering every update/improvements questions.