Using the configurations, you can specify the files to bundle, and where to bundle them. By default, they're put into a bundle file that gets updated on extension updates. It can also bundle into separate (named) files for use elsewhere (like my System - HTTP/2 Push plugin). You can see it in use on this site - right now!
I'm testing your Bundler and I have an issue.
For now i'm testing with css only and the blundler outputs a bundled css file which aggregate all the css files I want. So this part is fine but the problem is that some (or all) original files are not removed from the output.
So, for example, the originals files are mycss1.css and mycss2.css and in the output there is mycss1.css, mycss2.css AND the newly created bundledcss.css.
I've tested on 2 websites, locally and online, with the same results.