I just don’t know if there’s any point in even having the discussion with him because I know I’ll get nothing back except aggro. Denial that it’s a problem, anger from him mockery from him sarcasm from him. He’ll tell me I’m over reacting being over dramatic and ridiculous.
Then, no. I wouldn't say a word about it.
Boundaries are FOR YOU, not AGAINST HIM. You don't need to verbalize them, he doesn't need to accept them. They're still legit & real.
You just need to get comfortable with yourself enforcing them & with their judgment & discomfort - without prioritizing it ahead of your needs.
Baby steps - don't be too hard on yourself for not running like marathoner just yet.