I'm getting my ducks in a row and trying to think a few steps ahead. If he wants to do 50:50, how do others manage the practical responsibilities of children. E.g. dental appointments, doctors, buying uniform, childcare arrangements, school stuff? I do all this now, and can't see how we would share these responsibilities. Would I still be doing all this and just telling him when to take them to appointments. This would cause friction and be worse than it is now. Now I just get on with it all. But if I have to explain what needs doing and check he's actually taken them to appointments, I'm still managing his parenting and spoon feeding him, and he's not taking responsibility for them - so not 50:50 in responsibilities, only time.
If I agree to carry on with this side of parenting, which I'd rather, then during my 50% we'll be doing all the boring stuff & appointments, while he gets to be Fun Dad and only focus on the easier side of parenting.
Examples of how you manage these parenting responsibilities under a 50:50 arrangement would be really helpful to hear. As I do it all now, happily, I just can't see a way to split it amicably where it doesn't cause upset or stress for the children if stuff doesn't happen. I don't want them impacted.