Addressing your issue, I have bumped the version number to 0.1.3 and made a change to the async method handling so that instances not available at the remote get added to the fail log correctly.
This doesn't explicitly address the fact that some instances are unfederated, but it will make the log results clean.
As for the federation issue, what I've initially found is that a user on an instance has to visit the remote instance for the home instance to be aware of this remote instance, and a user (could be a different user) has to subscribe to that instance for the posts to start federating. What is unclear is how a user on an instance visits a remote instance from the home instance, as this is implementation-specific and could vary from instanc to instance.