The Office.context.document.getFileAsync-API already supports PDF export. Unfortunately, the file format is PDF 1.8 whereas we need a PDF/A compatible export. It is possible to specify PDF/A when saving the PDF manually through the "Options" dialog in the Office application. Unfortunately, there is no (documented) way to specify the type of PDF in the getFileAsync-API. It would be great, if the API is expanded so that PDF/A compatibility can be requested as well (either with a new file format flag or as an option in the optional GetFileOptions-object).