The list is not long, but I have a decent relationship with all of my ex's. My ex husband of 9 years (who is staying with me for the holidays to see our boys and is nice enough to be doing the dishes right now lol), my ex partner of 10 years and the very few after that who have enriched my life in one way or another. One was a pain in my ass but it was worth it
It really comes down to maturity. I believe two mature people can depart without getting nasty as long as each person owns their stuff and doesnt try and blame the other for all the woes of the relationship.
It takes time to heal and minimal contact might be wise if there are hard feelings.