One unpleasant thing I've discovered is if you use a small repeating pattern on a floor, the whole area is saved as a single large image. It does not use patterns and transforms available in the SVG spec. This is probably one of the worst offenders for bloating the svg plan export. Even the hashed fill of the walls is turned into a massive image. So for every wall type used, and every floor texture used you will have an image spanning the extents of their use, which can be 1000's of pixels in both dimensions.
