I know this an old thread but the IRS changed the instructions to the Schedule D Tax Worksheet in 2020.  The very top of the worksheet now reads:

Complete this worksheet only if line 18 or line 19 of Schedule D is more than zero and lines 15 and 16 of Schedule D are gains or if you file Form 4952 and you have an amount on line 4e or 4g, even if you don’t need to file Schedule D. Otherwise, complete the Qualified Dividends and Capital Gain Tax Worksheet in the instructions for Forms 1040 and 1040-SR, line 16 (or in the instructions for Form 1040-NR, line 16) to figure your tax. Before completing this worksheet, complete Form 1040, 1040-SR, or 1040-NR through line 15.

If you don't use the QDCGT Worksheet then you don't have to adjust foreign source qualified dividend income.