===Reply=== 
 Another Co-conspirator also questioned #4. I agree, if Precinct sizes vary greatly. However in this application: Precincts are supposed to have "approximately equal" populations. Due to evolving boundaries between 10-yr Redistricting, our Precincts now vary randomly (24 to 2800) most Avg 970 Voters/Pct. My thinking was: In the extreme, extracting one big-Precinct out of each Pass would require <=119-Passes vs. 7-binary-Passes. Extracting the bigger-ones early could help, IF there are simple-rules for which PctKeys to sort-out first. I'll look at that. 

 Back to the Wikipedia "Sorting Algorithms"  I may attempt a brief reference to "Physical Sorts." There are many sorting tasks (Apples, Ballots, Logs, Lumber, Mail, etc.) that are done manually. When large populations, these can benefit from underlying mathematical principles  while recognizing physical limitations. It takes both.