Wow, what an awesome thread!
I, also, have been struggling with curves and until now, have been getting around the issue by using an overstitch wheel to mark the stitch location on curves then continuing on the straight runs with either my 1 1/2" or 1/2" pricking irons.
Just spent about 30 minutes at the bench using UnionCraft's technique and .... by golly, I think I got it!
My overstitch wheel will now be used for what it was intended.
Thanks to all for sharing!
Bob