I am using an arrangement of elbows with distance mating to set up the pipe matrix, the pipe is given a configuration name, then extruded to surface, this gives me dynamic control of miltiple pipe length by moving the elbows.  I want to extract these lengths which were extruded in the "up to surface" condition.  The only way I can do it is to measure the pipe length and set D1@Boss-Extrude1 which then extracts to the BOM just fine.  There must be a hidden variable which remembers the last distance used in the extrude to surface condition.  I can open the individual pipes and measure them accurately, but I cannot extract these values to the BOM.