I've seen this behavior in Openrocket for some time, and just verified it in the current 15. 03 version. I don't see the simulation or the plot taking into account the motor delay specified in Motors & Configuration. When selecting a motor in Motor Configs, you can manually change the delay time, either to an arbitrary number of seconds, or to a preset number of seconds defined by the motor file. The program accepts this for display purposes, but when you run simulations for, say, 6, 8, 10, or 14 second delays, the simulation calculates the deployment velocity as though the motor was the 14 second delay. The plot shows parachute deployment at 14 seconds after burnout. Openrocket calculates the optimal delay, but it won't simulate a flight with a delay set by the user close to the optimal delay. Is this a known defect? Or am I missing something in the motors & configurations screen?