Beamer to pptx via LibreOffice.

Notes on getting your beamer slides into PowerPoint via LibreOffice without too much postediting. (AKA boss asks you for a few quick slides from a recent presentation. Gah, I wish I'd figured out the tricks below last Monday)

Standard procedure:

• Open PDF in LibreOffice Draw. 
• Save as ODP (or as odg and rename the extension to odp).
• Open in Impress. Fix display issues. Save as PPTX. Pray.

How to prepare your LaTeX source in order to minimise postediting:

• Use a recent libreoffice. There were some improvements of the PDF import with regard to text spacing in 2014 which should have been implemented by version 5.x.
• Speaking of text spacing: avoid justification. Best switch it off globally with the ragged2e package.
• Don't use PDF figures. Convert to PNG if necessary.
• Forget about conversion-proofing equations, take screenshots and add them afterwards as pictures. They will get screwed up during PDF import and then there's the issue of LibreOffice vs. PowerPoint math editors.
• Use LuaLaTeX with a Microsoft system TTF font and switch off ligatures. (note setsansfont vs. setmainfont for beamer!)
• Don't worry about advanced figure/text block positioning with columns or tikz pictures.  That stuff transferred surprisingly well.

Minimum example:

\documentclass{beamer}
\usepackage[document]{ragged2e}
\usepackage{fontspec}
\setsansfont[Ligatures = {NoRequired, NoCommon, NoContextual}]{Arial}
\usepackage{lipsum}
\begin{document}
 \frame{\frametitle{Lorem Ipsum}\lipsum[1]}
\end{document}