>>1504543The way I normally do it is to duplicate the layer containing the lineart, use the duplicate to create a Live Paint object (making sure that the colour of the fills is different to any lineart), expand the Live Paint object, ungroup it, select all of the Live Paint paths using Select-Same Appearance, invert the selection and delete the lineart "chunks" from the live paint.
That leaves you with a layer full of lineart, and a layer full of fills to manipulate how you please.
Also, this image is relevant - when you look at the image zoomed out, you get the white outline, but zooming in on it you'll see that the Live Paint is a perfect fit (though of course, expanding even by 0.1px gets rid of even that).
