Apologies if this feedback is undesirable, as you've done a lot of great work here.

I don't think it makes sense to even have an `init` method if you're going to run it automatically on `require`. It's sort of implied. To me your `init` method is more useful if you grab the module and only init if `options.sourceMap` is true, thus saving a bit of overhead. You'd have to do a bit of refactoring, but I can help if you'd like.