I'm going to use the solution below for my case, but I want to hear 2nd opinion.
Solution is: I arbitrarily divide my "totals" from "Covered Short−Term Gains or Losses on Net Proceeds" of 1099B for 2 huge individual sales - each of them will be less then "10,000,000.00" (this division I make arbitrarily because I's hard to take out from 10000 transactions only "wash sale" sales).
For one of them (let's say sale "AAA") I make "totals" wash sale adjustment from 1099B.
The other (let's say sale "BBB") can be just ordinary sale without any adjustments and may be with "0" gain - just to have sum of these 2 sales to match the "totals" numbers of my 1099B.
The question IS: does it make sense to set adjustment code "M" for sale "BBB" to declare it as "aggregated of multiply sales without adjustments"?
Per my understanding in any of case above (or with sale "BBB" as "regular" or as "aggregated") I don't need to mail IRS the "big shoe box" of paper (more then 5000 pages of my 1099B).
