The kaleidoscope quilts that I sew have hundreds of curved seams. Don't know about Wonder Tape.
I clip the "crust" piece: fold in half-clip there--then once on each half (3 slits) Needless to say, don't clip past SA.
Then, I fold the "pie" to find center. Line that up with the middle slit on the crust piece. Pin it.
After that, pin each end.
When I stitch, the piece is not flat. I sort of pull it upward and stitch around the curve.