Also Karch won't let her jump-serve anyway. Which is her specialty so bringing her for serving will never work.
He made an exemption for her before early in her NT career. So its not exactly inconceivable that he would do it again just for her...if he thinks it would help them win. But like serdar said its not a good idea anyway especially if we're only bringing her as a serving sub. So her serving is not enough to get her to Tokyo. She needs to prove that she can be the number 1 setter and thats tough a mountain to climb this late in the season.