I'm still getting familiar with my 560 (it was a second hand) and it would extend out about 4 feet of material the last time I loaded it. I couldn't rewind it beyond a certain point either so it all went to waste. How are you only scrapping 6-10 inches?
It should only load 1-2" into the printer. I'm not sure why yours loads 4 ft... Must be a setting or something is wrong. I know you can tell it to load xx inches before it prints, I turned that off. I usually extend it until it gets passed the "hump" in the heater... Once its extended enough to lay flat inside the curing module it's good to go. Usually it wastes 10" on cheap material / reflectives... Car wrap material I can print with near no waste.
4ft is insane though! Not sure why it'd preload that much.