The only thing that would put a hamper on her ability to do something similar to him is Trump's lack of care when it comes to perjuring himself on a debate stage. If this was a formal hearing with formal consequences, her ability to make him look bad is much bolstered. On a TV stage where he can just lie and say dumb juvenile things? Probably a little less impactful, but still will be fun to watch.
I also recall she landed some really good body shots on Biden in the '20 primaries. They were pretty obviously scripted, but they still hit hard. It's practically the only thing I remember about her primary run.
Pretty much this. Since most presidential debates have abandoned fact-checking for this and the previous election, he's free to lie, and nobody but the other candidate can call her on it.
FWIW, simply being a successful prosecutor doesn't make someone competent. Harris is competent, but that's not the reason why she was successful as a prosecutor. Prosecutors have the entire weight of the state behind them, which leads to most people taking plea deals. Even bad prosecutors end up putting tons of people in jail.