They have proper names in the Google Drive folder where they are stored. Not sure why those Google Drive names aren’t always attached to the PDF when you download it… must be some technical reason for this?
It’s a bug, we are aware of it. We actually set the download names very carefully to something reasonable. But with some recent Chrome update, Chrome ignores the HTML5 download= attribute for files living in Chrome extensions. It’s a security thing and makes sense.
We’re sorry, we have not prioritized implementing a workaround mainly because the whole viewer should be obsolete soon and replaced with our new viewer. There are other issues with it and that’s why we never took of the beta label…
User-defined structure for naming would be nice, but I like the default -- format. My only complaint is that there are spaces. This makes sharing across platforms/repositories difficult. Also, a truncated title would be sweet.