Then the listed script (and/or the improved version from adafriut) may do more for you. It is my sense that they can do a complete (or at least more complete, I don't know what they do for breadboard for instance) conversion but are not that easy to use. Many of the sparkfun parts in core are from that conversion program I think. Yes Fritzing is as far as I know unique in breadboard view and while it has bugs it also has source if we are smart enough to improve it.
Peter