I've looked into the new Safe Harbor Elections that you are referencing. 

To get the calculation to work in ProSeries you would simply fill out the Qualified Business Income Deduction Info Smart Worksheet at the bottom of your Schedule E Worksheet. 

If the IRS needs an election statement to go with it, this election statement has not been added to ProSeries 2018 so it would need to be added on the Preparer Notes worksheet or via a PDF Attachment. 

https://accountants-community.intuit.com/articles/1605889-individual-using-preparer-notes-for-e-file... shows you how to use the Preparer Notes. 

https://accountants-community.intuit.com/articles/1606302-attaching-pdf-files-to-federal-or-state-in... shows you how to add a PDF attachment to the return.