We looked at the Kino situation quite a bit to make sure it applied, but based on the evidence, they deserve it.
-Kino corrects people who used both male and female pronouns for them. 'I'm not 'insert gender', I'm Kino'
-Scene where they try out using 'boku' to self-identify, and makes a comment it suits them better.
Both are casually said, so its not a surprise if you don't remember them.
Its basically as close as you can get without them literally saying 'hello, I'm non-binary' :p And since most people don't do that, especially in Japanese media, it takes evidence for us to use the tag, which is why we are using it very carefully and only with some sort of proof.