My suggestion is, if you find yourself making conncession with nothing in return, just stop talking, and disagree with everything. In CA, mediation is non-binding, and the judge can't consider your refusal to cooperate against you, even if the mediator makes a strong point of this in the report. I'm not suggesting go out of your way to be intransigeant, but I am suggesting that you shouldn't feel pressured (particularly by the mediator) to make concessions that won't help your case.
If you are the father, the mediator will sometimes promise you that your case will move toward joint custody over time, even if you have less timeshare now. This is a blatant lie, because there is no mechanism in the laws, or the court process to bring this about. If you hear this lie, just turn it around and tell them that you will be happy to be the custodial parent now, and will give up some of your timeshare over time. Don't fall for this lie, or it will cost you big. Another thing, don't sign or agree to anything in mediation unless you are sure it will help your case, and your attorney has told you so.
You have a move away case, and you have to be extra careful. Good Luck.