[RMMZ] CAN PARALLAX IMAGES BE 'ZOOMED' OUT?

There's probably a plugin that can do it, and someone who knows can give you that answer, but my suggestion is that you just rescale the actual file to a smaller size in Gimp, or GraphicsGale, or some other image editing software. Way easier than dumping potentially conflicting code in your game.

EDIT: Make sure you know the resolution of the game and scale the image to that size. You can actually find that out in your plugins manager, in the first plugin.