Hueman is great theme, and so far I am loving it! Though I am quite interested in getting it to work with YARPP as well.
What constitute "related post" are quite subjective matter,
alx_related_posts might have been a little too random for my own taste.
Do you recommend changing the function code myself, seems like they will be overwritten the next time theme is updated.
So my best option without modifying YARPP or Hueman appear to be embedding YARPP automatically, then disable Related Post in Hueman.
Maybe there can be better way to handle this?