Well it’s not black and white, you make it sound like people who maintain boundaries are not nice and loving people but are cold and distant. I don’t think being nice means have no boundaries and having firmer boundaries makes one is not nice.

I see no need to be cold and distant when anyone (doesn’t matter if it’s soon to be ex or a neighbor) faces death or illness in the family. Expressing your condolences to him or feeling sad that his dad might die isn’t wrong. You just don’t need to be sucked into drama and manipulation though, it doesn’t mean you shouldn’t be compassionate or good person. One doesn’t exclude the other.

Also there is a happy medium somewhere in between, you alternate between fighting with him yelling the most vile words (for the good reason) and being loving and compassionate the next day spending hours on the phone with him. That’s kind of drama was taking place while you were married, a lot, vicious fights alternating with loveydovey stuff. Now when you are in a process of divorce, similar drama takes place. Hot and cold. It’s extreme and might not be particularly healthy

You could be a nice person and do the right things by your exes but in moderation and with your eyes peeled. If he is an abuser and narcissist, you need to be careful. Why do you think his ex wife still talks to him, he is sucking her right in. Or why his exes allowed him to store crap in their places for years! He is that good. He is a master manipulator and a user