28th February 2016
If you want to export Notes to a PDF from LibreOffice Impress 5,
and dutifully set the appropriate checkbox in PDF export dialog,
then you will get all slides twice: first just all the slides as with usual PDF export, and then all the Notes pages.
There is an easy solution to get Notes-only without editing the PDF.
If you have a PDf printer installed (most Linux distributions, and Windows 10), just do File -> Print from Impress,
then under the Print sub-header choose Notes from the Document drop-down (see picture).
Make sure to set the proper paper format for the PDF printer (A4 in my case).
Then print, and save the resulting PDF.