metrics graphs in vector format
It would be nice if it were possible to download PDF and/or SVG versions of the graphs from the metrics website. R has generic support for this, all you need to do is add PDF and/or SVG options to the "resolution" dropdowns, map those to URLs with the appropriate file extension (https://metrics.torproject.org/direct-users.pdf?... for instance) and map those to calls to the existing R scripting. ggsave() will do the rest.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information