"We" don't. We are mostly other users in this public forum, not TurboTax staff.
I would guess that this was a business decision as to whether to put in the software effort for a complex one-time form.
Here's the details on the money back guarantee if the other method would have given you a larger refund..
<a rel="nofollow" target="_blank" href="
https://ttlc.intuit.com/questions/1908546-what-is-your-maximum-refund-or-tax-savings-guarantee-or-yo...>
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*
