I guess NC is pretty controversial..I can only add my own experience NC
Wish I had the first time right off the bat....HAD to this second time. Currently NC at 3 years.
IMHO If the MLCer is driving you insane, being verbally abusive, is (or has been) physically abusive, yelling, threatening trying to intimidate and control you, not respecting boundaries, dragging you into drama with the kids or the ow/om or filling you in on the current sex life with an OM/OW or any other thing you feel is being said to intentionally hurt you. Sometimes just seeing them or talking like almost normal people brings pain. It's the only way to protect your sanity and heal. You are allowed to say " I cannot or will not do this" You are protecting you. Then take whatever time you may need to work on you and get stronger.
Maybe some of you will read the list and say some of this goes without saying. " Like well if he (or she ) ever hit me that would be my limit" or "If they are living with the ow/om that would be my limit" Only you can decide when you have had enough.
NC is for you so you can focus on you,heal, learn to love yourself, be grateful, and move forward.