In what key way does the function of the discourse marker '게다가' differ from '더욱이' when structuring a persuasive argument?

The key difference lies in the scope and nature of the added information within the persuasive argument. '게다가' introduces an additional point or piece of information that is *relativelyindependent of the previous statement. It acts as a simple additive, building upon the initial claim with a new, supplementary fact or reason. It's....