Then what would we call someone who makes the dietary choice but none of the other lifestyle choices? How would they identify in a restaurant setting? The answer is “vegan”. In the same way that I’m vegetarian but don’t care if I wear leather shoes.

I’m not saying you’re wrong, I’m saying that English lacks the words that would let you be precise. We need a word for people who are vegan in diet, and don’t care to bother the rest of the world about it. That’s why OPs question keeps coming up.