"...Taxpayers may rely on the proposed regulations for tax years of beneficiaries beginning after 2017 and before the final regulations are published."

Per the IRS notice I attached - you can used the proposed regulation until a final one is issued.

AND - only "you" the preparer, after consultation with the preparer of the F 1041, can determine if the excess deductions qualify to be taken *above the line* per § 67(e).  To not research the issue further is a disservice to your client.