I appreciate that Carol illustrates her technique using fabric that ravels, as this scenario sometimes adds to the challenges of mastering this foot. Maybe I missed it (will go back and review), but I don't recall her addressing the handling of the corner where two rolled hems meet. I imagine you'd just stop creating the hem with the foot and form the edge with the aid of an awl or something pointed for the remaining inch or so, then just stitch to secure.

Thank you for tackling this subject, Carol!