Okay, so why don't you fork the project, and create your simple Foo/UTF8 methods, and confirm that they are the correct Foo/UTF8 methods for each of the document formats supported.
I'm not saying that it's really all that hard, but there are multiple document formats, and versions of those formats. The author obviously didn't need unicode support, so didn't test for it. I'm sure test cases, and a pull request would be welcome.