Currently one of the main downfalls when working within excel documents (or other office programs) and sharepoint is that when you save a pdf to sharepoint that has mandatory metadata fields, the pdf requires manual checking-in once created and does not appear for other users until it is checked in. It is essentially in no-mans land and there is no error message or notification to advise the user that this is the case. The only way to find these documents is by the Site Owner in the Document Library Settings and "Manage Files which have no checked in version".

The oneplacedocs save as function saves a pdf to SharePoint whilst also prompting for the metadata and checks the file in. The limitation with this is that when using excel, it prints the entirety of the document to pdf (even hidden tabs)