There's a weight that hasn't been pressing down on me for roughly three years. I've grown in so many ways as well. It was a great decision that's only improved our immediate family group in almost every way.
That being said, my sister I have maintained contact with is getting married soon. And those I've cut out will be there. Little bit nervous about that and hope they don't cause a scene at the wedding. I offered to bow out but she doesn't want that. Our narcissistic sister (that she made her maid of honor) froze her out and refused to talk to her for two weeks when she found out was going to the wedding.
This sounds eerily like my exact situation. It's only 3 other siblings for me though. I'll have to see her in roughly a month at my sister's wedding though. Kinda nervous, not gonna lie. But as you said I'm more at peace than I've ever been. Wife, kids, and I are all solid and growing together without that toxic cycle weighing us down anymore.