@TaxGuyBill "In some cases it can contain important information that is not on the 1040X, and may help the IRS agent process it."
Avoid "Little Man With Green Eyeshade Syndrome." These are not "agents" who are perusing the package, in the sense of revenue agents as we know the term. They are clerks, working in a big paperwork factory, who have quotas to meet and procedures to follow. Many go to Block to get their own returns done. Showing them something they already have and must verify anyway, just wastes everyone's time.
If IRS considered other information important, it would require it on a 1040-X. Keep in mind that IRS has a copy of the original return already, and is required to compare it with the numbers shown on the 1040-X. If you prepared both the original and the amended return, you know that the numbers will match. But IRS doesn't know that, so they ignore the original 1040, which may have been edited during processing. This is what the IRS clerk does:
Master File verification is required on all amended returns prior to:
Inputting an adjustment
Master File verification requires, but is not limited to, the comparison of the Adjusted Gross Income (AGI-Line 1), Taxable Income (TXI-Line 5), and Total Tax (TC 150 -Line 11) on Form 1040-X, in Column A with IMFOL or TXMOD.
If Line 1, 5 and 11, Column A or any combination of these lines does not match TXMOD and no math error (MTH-ERR) is present, math verification is required.
Be sure to consider all adjustments previously made on the account. Work the duplicate or amended return without requesting the original return, if possible.