Hooo okay, I'm still at the beginning of the game that could be the thing (I never really went that far). So the latest scenes does work using the actual sliders with SFX if I understand correctly.
Happy to hear that you'll add moans to scenes and want to do it right (Your game will be part of the finest NSF/VN with this add (as AIrevolution, COR, Goddesses' whim, MHF, etc.)
Looking forward to it !