I’m lucky that when it comes to arguments I’m pretty good. I have a competitive streak that skews the flight/fight response to all out war when it comes to a discussion or disagreement that means I go straight for what I want to say right away.
The occasions when I have regrets about things not said are so rare that I don’t even recall if there are any. It’s like asking me to talk about a time I was wrong. It just doesn’t happen. Being a big believer in attack being the best form of defence the idea of a perfect comeback suggests that you were not winning the battle.