My husband is trying to figure out a new visitation/parenting plan for his daughter for high school. Current schedule is about 40/60 split. Looking at 45/50 or 50/50 split.

Background: Father was primary caretaker of 2 daughters until about age 7 and 12. When I say primary I mean that he took them to school, made thier lunches, picked them up from school, made their dinner, took them to appointments, etc. Mom worked 45 plus hours a week and was often gone out of the home for her own hobbies. Whenever the divorce happened he wanted primary custody since he was the primary caretaker. (and she was the "breadwinner") He still worked full-time but had a very flexible work schedule. Anyway he was given temporary primary joint custody, and Mom was very upset. (Both daughters talked to the judge as well, which is another reason he was given custody) She continued to drag out the rest of the divorce process until he didn't have money left and decided in mediation to agree that she could be "primary resident" parent and they would have joint custody. There was no child support ordered since she made twice as much money as him.

The schedule is currently this (was different for the first few years) .Dad has 2 overnights on even weeks and Thur-Sun 6pm on odd weeks. Mother has over the past few years sent threatening letters from her lawyer for numerous things, first trying to get child support,(even though she was making now three times as much money as him) then trying to modify visitation so that it was closer to a "standard schedule" which reduced his time with his daughters.

He feels this schedule is already limiting his time with his daughters. One daughter is turning 18 and moving out this summer and the other is starting high school. He would like to propose at schedule where he has his daughter for Wed/Thur night and Odd weekends (which is pretty much what he has now, but this schedule adds one night every two weeks). He also has thought of a 7-day rotating schedule (One week with mom, one week with dad). They only live 4 miles apart.

His daughter has already voiced that she wishes she had more time with him and that she doesn't like transitioning during the school week (especially not more than once).

We are pretty sure mom is not going to agree to give him anymore time. What should he do? Try to talk to her about it, and then fill for modifcation in the court? We are afraid of spending lots of money and coming out with the same schedule. I understand that from mom's prespective she doens't want to give up any time, but it would seem that she would be happy that the father is scuh a great dad and wants to be more involved.
Thanks for reading and any thoughts you may have.