I presonally don't see how could you disengage to the point where you're not affected by what your RAH says to you.
My AH has been in recovery for over 3 months now. I know it must be hard for him, and I respect that, I'm willing to help him with anything he asks the help for, but no way I'd put up with him talking that way to me.
The way I see it it's a two way street, I'm there for him, understanding his struggles, being tolerant, not mentioning the past, doing pretty much the same things you said you're doing too, but I ask for something in return: Respect. Nothing more.
And I have made that very clear to my RAH. And he does give me that respect, because he knows it is not only me any more that is going to do all the work. I'm sorry that the things are tough for him right now, but he has to deal with them himself, and treating me like sh*t is not going to help him in any way.
I think it all comes down to healthy boundaries.
His sobriety depends on him only. Of course there are things you can do to make it easier on him, but by what you said you'll already doing them all: you'll there for him, you respect him. Letting him treat you this way is not helping anyone.
And why exactly would you want to put up with that kind of thing? Is it from the fear that if you don't he might start drinking again? If that is the case maybe you should think carefully about it.
IMHO we teach others how to treat us. If you don't stand up for yourself no one else will. He is not going to miraculously get it, unless there are consequences that will make him get it.
My RAH knows if he treats me poorly or if he stars drinking again, or starts doing any other stupid thing we are over and done with. He knows that if he wants our marriage to work he has to work it too. And most importantly he knows I'm not making idle threats and more, he knows I mean every word I say and it is making him think twice.
And it is working for us for now, and I believe it we keep giving each other respect, things will keep on getting better.
I don't know if this helps, I hope it does.
I wish you well