In a negotiation look for what the other side is motivated by and seek to give it to them. Both must save face, both must get what they want, for it to be a success.
You don't win a negotiation by beating the other side over the head with your terms. In that event it just becomes a game of chicken over who's willing to give more money to the lawyers.
So try again to see if you can limit the number of transitions and not exceed, what was it, 5 days she was willing to go but not 6? Show good faith that you're working with her while not giving up on the 50%. And demonstrate that you're being reasonable. Good luck getting an older kid up and out before 9am on a Saturday without the kid resenting the heck out of you. But I digress. Use smart negotiating techniques to find a solution you both think is best.
I know this disregards the fact that you're both mad at each other and both think the other is being difficult. That's on purpose. Those are unproductive to your goal.
Adinva 51, S20, S18 M24 total 6/15/11-12/1/12 From IDLY to H moving out 9/15/15-3/7/17 From negotiating SA to final D at age 50 5/8/17-now: New relationship with an old friend __ Happiness is a warm puppy.