Thanks TaxDavey. Your last statement is more accurate than my, somewhat emotive, question.
I agree with your evaluation that, except for a few exceptions, it is optional whether you use the worksheet for line 18 and also adjust values in Line 1a. I think that if your foreign taxes are not related to overseas qualified dividends and capital gains then it may be beneficial to take the option of using the Worksheet - this is my case.
So the more accurate question to the TurboTax experts is: For Form 1116, how does one invoke the Worksheet for Line 18 and any subsequent adjustment to Line 1a?
