Your might try the Pfaff.com website. I have a 7570 and I have to select that function whenever I want it to happen. I'm not sure why the machine would know if I need to tie off otherwise. I am constantly starting and stopping when I work at the machine (not always at the end of a seam) and raising/lowering the presser foot.
I've only used the tie off stitch when sewing garments. I don't use that particular function when I piece because I always am sewing over another seam. Where would you use it when you quilt?
By the way, sewing on a button using your machine is the only way to go. If you have to handsew one it might end up in the terminal "round-to-it" repair pile.