It occurred to me that a basic effor/time saving principle of agile project management is that you don’t try to plan everything up front, because you don’t need to!
The fact that for example getting a site live ready by a certain date requires a change to the URL pointing means you only need to worry about it when you get close to the event, as each event is connected in reality to another (‘one thing leads to another’ to slice the folk wisdom). Call it ‘managing complexity’ if you like.