Naturally, some people may want to display particular exotic kinds which might not extend to the broader public. A chicken post type certainly falls under this umbrella as I wouldn’t expect that other than for novelty, obsessive IndieWeb post kinds completeness, or for a very small handful of specialized farming, juggling, or comedy websites that anyone else in their right mind would really want to be doing a lot of posting about chickens on their site.
David Shanske, the plugin’s creator, has made it possible to create a sub-plugin of sorts so that one can add one-off support to these types using a variety of filters and functions. This could be useful so that updates to the plugin don’t overwrite one’s work and require adding the pieces outlined above back in again. Sadly, this is a tad beyond my present abilities, so I won’t address it further at the moment other than to say that it’s possible and perhaps someone might document it for others to use a similar template in the future.
Chris, when I have some free time, I think I'll add a beer kind to use with my Untappd activity.