I've found that variable constraints are highly effective when support lines are perpendicular to the alignment. However, when a skew is introduced to these support lines, a variable constraint continues to function perpendicular to the alignment or by station.

It would be beneficial if variable constraints could adjust to identify and accommodate the skew assigned to the support lines. Potential solutions could include an automatic adjustment for the skew, or the addition of a "follow skew" check box in the Variable Constraint window. While the menu can continue to be by station, this should primarily apply only at the origin point, or centerline/alignment, and then project outward at the desired skew angle.

Consider the following scenario: an approach slab measuring 1'-2" thickens at a 2:1 slope to 1'-4" over the abutment. the approach slab rests on the abutment 1'-1 1/2". With a skew value of 15 degrees applied to the support lines, the constraints need to adjust accordingly.