I've never tried not washing Warm & Natural on a quilt I intended for a destination other than the wall. That's 3 inches on a 100-inch quilt... what does that look like? Is it noticeable? It would seem like it would be.
I hand soak the batting and then either lay it flat or tumble it.... tumbling it sometimes makes it pill up a bit, though, so I have to pick at it before using it... so I usually just wring it and lay it out on big beach towels--in the sun in the summer it dries quickly, in the winter indoors I swap the wet towels after the first several minutes. The wringing, done gently, doesn't seem to adversely affect it.