[ev0lv]

>>Deliberately misgendering someone goes beyond just tacky and into offensive.

Strong disagree. You need to consider what is actually offensive, and when labeling it so is simply hyperbole. Boy who cried wolf.

[philjohn]

You're free to disagree, but you're wrong.

Gender identity and how someone refers to themselves is a core part of their identity. Deliberately (as in, going out of your way, not as a mistake, but as a conscious act) is indeed offensive. And moreover there's zero need for it, unless your purpose is to cause offense.