The corners of my chin and ATG is what prompted me to start using a scything stroke.
With the heel about mid point on the under side of my chin I do a scything stroke as I round the corner,
As I crest the top of the round point/corner of my chin the motion continues up but the rotation of the scythe changes.
I end up at my lower lip parallel to it.
As I explain it and think about it is a bit of an S scything stroke if that makes sense.

From the title of the thread I was going to say you needed longer arms