Hey,
I think boundaries need to be for you and not for him.
Because your boundaries need to be something you have control over.
A boundary can be "if he brings alcohol in the house, I will leave" or "if he gets drunk when we're out with friends, I will leave him and drive home by myself" or something like that.
When you're setting up "boundaries" for him, it's not really boundaries, but a way of trying to control his behavior.
Which you can't.
You can only control your own.