Wouldn't a clause being added that required some form of obvious progress that your company plans to directly use the IP they are holding or lose it to the public be sufficient to prevent companies like MPEG LA from just using it to sue others? These things were meant to protect innovation, so require copyright/patent holders to be innovating or lose it so someone else can. I know "innovation" is vague but as someone else just noted on HN recently, the legal system is good at making rules even on abstract concepts.