I've abbreviated the views of two experts on legal writing below. Neither view is as all-or-nothing as I've portrayed it here, but this nicely frames the question of using parentheticals. What's your preference?
Paragraphs filled with parenthetical explanations are painful to read. If a case supports a proposition you are advancing, state the basis for that support in plain, expository prose in the text without the parenthetical. Reserve parenthetical explanations for rare situations.
As a law clerk to a judge, I learned that judges consider citations without parentheticals useless. The judge I worked for would not let us prepare draft opinions without citation parentheticals. In practice, my briefs would not cite a case without a parenthetical. To avoid readability problems, put supplemental authorities with parentheticals in footnotes.