For 2017, I'm entering the foreign tax credit total directly on Form 1040, Line 48.  No flags or warnings when this amount exceeds $600.

Even if the foreign tax does not exceed $300 ($600 MFJ), F.1116 may still be required.  As you may already be aware, there are other conditions for making that election, that not all passive income is qualified passive income, and that some passive income that is otherwise qualified may actually need to be reclassed as high-taxed income, which would disqualify the taxpayer from making the election.