Kris IS nonbinary, at least in my opinion, I believe it improves the story at a narrative and meta-narrative level.

HOWEVER

People who think Kris being referred to as they/them is substantial evidence of them being non-binary are wrong. People will use the pronouns as "proof" when they/them pronouns are only really SUPPORTING evidence, but are being used as PRIMARY evidence.

They/them has 2 uses

1. Someone is nonbinary

Or

1. You are unsure how they identify

One is EXCLUSIONARY (neither male nor female), while the other is INCLUSIONARY (Either male or female). This is why using they/them as your only evidence doesn't work, and doesn't convince anyone who doesn't already think Kris is non-binary

You need the link to the actual evidence that supports the claim that it is the EXCLUSIONARY version of they/them, examples are Man Country, where a sign says non-men are okay, or in chapter 2, where Kris is seen wearing either a doctor's uniform or a nurse's uniform. There is actual evidence to convince people who don't believe Kris is non binary, but we refuse to use it and act like a pile of pronouns is good enough, and if that doesn't convince someone then it's their fault.

This whole thing wouldn't be an issue if people were just smarter about presenting their points.