Ah, as of right now there is no limit, but this will be changed to a limit of around 4 in the near future. I wanted to play around with it to see what seemed to work best.
What you experienced with the LOAD MORE button will get looked into, though, and at the very least that particular feature will get modified as the filters/feed settings get changed as well. Much to be done and I appreciate the feedback!
Limited to 4 authors: Why? I like it to be larger so I can create feeds on topic/tag and authors I like who post in selected tags. I would like to see at least 10 to 20 authors being able to configure.