Sorry my Maths was out earlier
I think your kids will start to notice less time with you and may try and get more. 12 is only a couple of years before they can start asserting themselves more. But 10 is still quite young.
So what did Cafcass recommend? Same time as before? I still think I'd appeal the magistrates decision, on the basis it's not in the childrens best interests, they need what they're used to - both parents involved in school life and supporting them, the youngest is only 10 and will struggle with the change and argue that the childrens wishes were expressed wishes, not ascertainable wishes, and these are their Mother's wishes.