The trade by trade rounding is absolutely NOT required by the IRS. If it were, then all the 1099-B worksheets using Boxes A and D would be rounded the same as those using Boxes B, C, E and F. TurboTax only started rounding the crypto trades (i.e. B, C, E and F) to allow their biggest clients to evade taxes. Those that aren't aware of this "feature" will probably end up paying more than necessary.
Last year I was advised by a member of the Office of the President to take advantage of the feature by splitting all profitable trades into amounts totaling less than $0.50 gains. This way you will not owe any taxes, a feature fully supported by TurboTax under the guise of "the IRS requires us to round this way".
