During the summer of 2019 the Vermont DMV will offer driver licenses with the gender listed as "other". A serendipitous change in the notary law goes into effect July 1, providing short certificates for most notarial acts. The certificates are so short that they do not contain any pronouns (he, she, they, etc.). So the notary will not have to wonder how to word a certificate for a person requesting a notarial act who does not self-identify as male or female.
This contrasts with with California, which has mandatory certificate wording for many notarial acts which include pronouns, which do not have any provision for a pronoun for a nonbinary person, and which does issue driver licenses with the gender listed as "X". Apparently serendipity does not occur in California.