Yes, you can force the calculation by using the amount you calculate for each loan as the Box 2 Outstanding Mortgage Balance amount. If this brings the total of your mortgage balance below $750,000 for the year, then you should be able to file without the finalized worksheet.
If you do this, keep a record of your calculations and how you determined the number, since it is different than what is reported on the form. The form itself is not reported to the IRS, so this will not cause an automatic rejection or trigger an audit, but you will want to be able to defend your position in case they do ask.
If your outstanding mortgage balance total is above $750,000 even after using the average mortgage balance for each loan, you may have to wait for the finalized worksheet.
