I called IRS again, this time a different rep confirmed that what I’m doing is correct. I don’t need to send any attachments to them, electronically or by mail, as long as the transactions that have an adjustment are listed on 8949. So that’s how I will file taxes going forward, hopefully that won’t increase the chance of an audit.
Interestingly, he said that IRS actually gets each transaction on 1099-B reported to them, not just the totals. Makes me wonder why we even need to include Wash sale adjustment for each transaction on 8949. IRS will already have the wash sale amount since my broker reported it on 1099-B.