It is indeed frustrating when TurboTax takes a "lazy" programming alternative for the 529-to-Roth conversion (someday, AI is going to put them out of business). I did want to mention that it's been my experience that TT treats an IRA contribution when the contributor makes too much money correctly, when input as a backdoor Roth conversion. It goes first into a traditional IRA, WITH A BASIS, because you make too much to take a deduction. The traditional IRA is then converted to a Roth IRA, and since it has a basis, this conversion is not taxed. You need to have no other IRAs, or you run into the prorata rule. You don't get a tax break on the contribution to the traditional IRA, but don't double-up on taxes for the conversion to a Roth account. There are a couple of posts that provide details on exactly how to get it into TT, so it all works out.
