Yeah. It's for developmental/experimental purposes; not really something you would want to use for emulation.
As long as you have an emulator installed, you don't need to download a plugin like that.
Unless you're like me and you like to use the plugin with the lowest file size and less excessive features...in which case, I would actually be using that plugin now, if there were some damn way to edit the controller config.
I'm somewhat surprised such an experimental plugin never had a source released for it (not that I, as of my current progress, would be able to make much use of it).