You are correct, the program does not let you override Form 8962.
The Iterative Calculation sometimes does not work out cleanly, and there is no clear directly for what to do with the 'odd' amount left over, so TurboTax just puts it on Schedule A (rather than trying to work it into the SEHI deduction and PTC credit).
First thing to consider is if you are interested in contributing to a Traditional IRA. Sometimes even a small contribution can alter the Iterative Calculation so it works out cleanly.
The other potential option is to go to your business section and look for the area where it asks you to enter non-Marketplace health insurance. Sometimes entering small amounts there can effectively create your own Iterative Calculation. Enter a small amount, see what it does to the SEHI deduction and the PTC, and then alter the amount on health insurance spot again to make closer adjustments. It doesn't always work, but it often will get you much closer.
