I am not sure what your current arrangements are, or how much time you each get with s12 but STBXW and I have a 3 on 3 off, 4 on 4 off agreement. I get my boys Wednesday, Thursday, Friday and Every other Saturday. STBXW gets them Every other Saturday, plus Sunday, Monday and Tuesday.
During the school year on Wednesday they ride the bus from her place to school and from school to my place. She picks them up at 9 am on Saturday, or on my long week she gets them at 12:30 on Sunday. No talks, no changes, no negotiations. S11 and S13 picked up on it in 2 weeks and they are really settled into the routine.


M42 W40
T17
M15
S13 S11
BD 7-14
A discovered 7-14
WAW moved out 10-3-14
D final 2-23-15