See the post below regarding the Supreme Court's decision last month in Ramos v. Louisiana, and a link to my post from last year explaining the decision's unlikely retroactive effect. Today, the Court granted cert in
Edwards v. Vannoy, No. 19-5807, to determine whether "the Supreme Court’s decision in Ramos v. Louisiana applies retroactively to cases on federal collateral review."
On a personal note, I spent half of my career prosecuting cases in Oregon, one of the two states that authorized non-unanimous verdicts. I can't recall that anybody ever challenged or complained about it. The rule presumably cut down on the number of hung juries, but not to any significant degree. Some defendants would probably prefer to take their chances on a 10-2 verdict to the expense and stress of multiple trials.