The IRS does trust your cost basis, but I have no doubt there is some backend check that flags things that are wildly off of what is expected. But I don't thin

The IRS does trust your cost basis, but I have no doubt there is some backend check that flags things that are wildly off of what is expected. But I don't think the tax prep industry lobbied for how RSUs cost-basis is captured. That's just a byproduct of the US tax code and requirements for reporting on 1099s from brokerages.