'Cutline JAM9' uses a SPLINE2 statement for the pretty part. This is OK, but it prevents us from having an easy masking function in the cutline.
Instead of a spline, use an trimmed ellipse. We can build the ellipse from a 900/4000 POLY2_A, which can have a fill, and stretch it with a MUL2.
The S looks good when 1/11 of the ellipse is trimmed off. After the MUL2, this is the same as 1/11 of the circle.
Need to figure out how much arc is left after that trim.
One side of the S will be filled. The other side will be filled except for the ellipse.
UPDATE: Done. That should hold for a while.