If it helps, he doesn't want to hurt your trans friends, it isn't a terminal value. If you could convince him that trans people and potentially-trans people will be better off with people respecting trans pronouns and teaching about transness in schools then he would change his behavior.
That would go about as well as trying to convince him of the benefits of Scientology. Most people, once they recognize a harmful ideology masquerading as a benign one, aren't likely to be convinced otherwise.
