Why are you asking about "preparer notes"? If you are a paid preparer you cannot use TurboTax to prepare tax returns for paying clients.
TurboTax provides for entering an explanation where it is required by IRS rules. The IRS does not want explanations that are not required by the rules. The IRS instructions for Form 1040 say "Don't attach correspondence or other items unless required to do so." If the IRS wants additional information, they will send you a letter asking for it.