"As for entering the basis, why couldn't there be a jump to a worksheet where you would add that in?"

And then the worksheet would lead to nowhere, because the partial liquidation might be paid over several years, and the basis is not yet reduced to zero?  And then the broker might be keeping track of it also, and when the final payment is made, it will report it on the 1099-B.  It would be like entering the cost of home improvements for 20 years, so you would have the information when the client finally sells the house.  IRS doesn't want the information, there is no need for the software to accumulate it, and investors should keep track of their basis with their own system, not one that I have to pay for when I buy tax software.