I agree on pretty much all of your points. I love seeing this in action in al-anon and in other group setting where people consciously practice similar principles. For example, I've noticed it's common for teachers in my recent studies to request something of this nature from the class at the beginning of a semester and then remind us of it when conflict occurs. (Isn't it great when these principles appear in the wider world?) When it's reciprocated, it's great and more than simply allowing me to function alongside people I might not personally like, it allows me the opportunity to learn things from that person that I might otherwise disregard, and that's often a valuable gift.

When it's not reciprocated, it can be very difficult, especially when it's someone you can't just disengage from. I know with my ex A, things reached a point where the abuse and outright malice from him made respect pretty much impossible and total disengagement was the only possible way I could protect myself or go forward. I think that's partly because we learn some of our unhealthy responses to abuse/ unfair treatment for a good reason.

When my ex-husband wouldn't stop calling and threatening me constantly, coming over and trying to force his way into my house etc I learned that if I acted completely insane, screaming into the phone, throwing things, saying crazy things, he would get rattled and leave me alone. It wasn't respectful to either of us for me to behave like that, it was just the only effective way I saw to make him leave me be. (Thankfully I learned about relying on the police etc instead a bit later haha. That's definitely the better option!) But my point is we learn some of these behaviours to protect ourselves and if someone is behaving in a threatening way it makes sense that we act out of self-preservation. I don't think it's fair to expect ourselves to immediately unlearn self-protection behaviours were might have spent a life-time building when we're constantly under fire from someone; I'm a big fan of being kind and understanding with ourselves first and foremost.

I don't know what the answer is to how to maintain this principle when dealing with abusive or unreasonable people that have a significant impact on us; my go-to response now is to simply disengage and if they persist, to refuse contact. But that doesn't work with closest/ live-in family and I haven't had to deal with an unreasonable partner for years now and don't think I ever will again, this issue being one of the primary reasons. Again, probably not a healthy response but one that keeps me safe.
I look forward to reading other's input and how they manage to treat abusive/ unreasonable people with respect when it is in their home and causing them harm.