I'm commenting here with my community member hat on and not as an Automattician as I have no involvement with the team(s) that manage this plugin or any inside knowledge.

It's on GitHub. Instead of jumping directly to discussion of forking it, why not open an issue or two on the features you'd like to see? If they're well received, write a patch and submit a pull request.

I mean this is exactly the same type of thing you'd do for WordPress. You'd open a Trac ticket and contribute a patch.

Just because a project doesn't have any recent new features doesn't necessarily mean that it's abandoned, it just often means that priority has been placed elsewhere. I know that's certainly the case with many of the plugins that I'd written and released personally.