Alternatively, hold the crown "in position" against eh line drawn on the fence and set the bevel to 0 and the miter to 45.
With the saw set at a 33.9 degree bevel and 31.6 on the table, we can cut crown on the flat.
By holding a jigsaw at he opposite angle of the miter, you can make an ideal back cut.
The aptly named "tappy" block helps adjust the crown into place.