Q. Is there any advantage to having the worksheet in my records along with the override value I had to provide to correct the mistake Turbo Tax appears to be making?
A. Simple answer: No. Theoretically, it's a document you could just give to the IRS, in case of an inquiry, but that's unlikely to be enough to satisfy them.
There are two things you didn't mention, in your post: 1. Are you eligible to claim the tuition credit (primarily is your income not too high). 2. Did the student have any scholataships. The usual reason for TT making the 529 partially taxable is that expenses have been allocated away from the 1099-Q and allocated to the tuition credit and/or scholarship.
