OK, I am getting into some more, ahem, "exotic" commercial motors. I have the 54mm AT K250 and it calls for the "extended" forward closure. I ordered the closure from Wildman on Black Saturday over 6 months ago, and I have frankly lost all hope in receiving it in time for my launches this year. Anyway, why the need for a longer forward closure, with presumably longer delay grain (called "smoke charge" in the instructions)? If the motor is to be flown plugged with no BP charge anyway, as I intend to do, then what is the purpose of the long delay element? Is it needed for proper propellant burn? Can I use the standard length closure/delay instead?