Frankly, serial numbers are an absolute pain in the ass, and I would much rather have never assigned anything until two minutes before they ship.
HOWEVER, c71 was a horrible wrench that got thrown at our heads and assigning numbers to close orders was the only solution we could see. Operation one and operation two happen in the same machine, they are done in sequential order. Operation three moves faster than one and two, so no problems there. The bottle neck is operation four, and this is NOT necessarily done in sequential order. Bead blasting, tumbling, quality control inspection, anodizing, none of that is necessarily in sequential order.
We will ship out in the best and most fair method we can, and our priority is chronological order. To everyone with a deposit, but not paid in full, I solemnly swear: We want your money, more than you want to part with it... I promise.