Unlike SolidWorks, Pro/E doesn't allow for the use of bend deductions. Our shop like a lot of shops use bend deductions to calculate flat sizes. We have our own BD charts that were made based upon actual test forms with different material thicknesses and bend radii. I can plut those charts into Solidworks and use the bend deductions. I know Pro/E has bend charts you can set up, but they are not based on bend deductions. Can PTC look at furture builds to support entering bend deductions?
based on geometric relation between radius of the bend and the thickness of material bend deduction doesn't depend on k factor (or y). if your material thikness is T and bend radius R deducion from driving length is: L=(T+R)tan((180-angle)/2) angle is between two sides. If you incorporate this equation in your design process you can determine you flat part before acctuall bending. I don't know if this help. BTW, let me know if this equation drives with your testing data. I've developed it and test it.
Steven, Pro/E has long supported custom bend tables for determining the length around a bend. Look thru the help files for more information or if you can't find it, post back and I'll explain how it's done.