Yes, that probably makes the best sense - except I'm not sure Form 8606 can be attached to Form 1041, since the top of the 2019 Form 8606 includes the statement "Attach to 2019 Form 1040, 1040-SR, or 1040-NR" (I have also been unable to find a way for Turbo Tax Business edition to add a Form 8606). Thus, I'm assuming the best way to justify the amount on Line 8 is to include a good - albeit very brief (due to space limitations) - description on the blank line of Line 8.
