Sheet Metal Bend Issue

Hey,

Is it possible to define the bend as radius and arc length, rather than radius and angle? I'm trying to get one of our components into a family table, and the drawing I have gives the length of the bend not the angle. I realize, of course, it's a simple math problem to get it from length to angle. While this gives an acceptable bend for the largest of the family of components, the smalles fails. I am thinking the failure is due to rounding error or perhaps the bend plane? Regardless, if I could just input the radius and length, it would solve the problem more elegantly. Any help would be appreciated.