My point was about the "it's impossible because of w,x,y,z etc." negativity so why bother, while not all the issues can be solved (with the lack of overrun being the biggest), the rest is do-able but multiple issues need resolving. The point I was responding to was around "no point in improving approach control because stepping back would then be required to make use of the improved capability as well", in which case there is a good incentive to implement stepping back at that pointMoorgate doesn't have tunnel space for runover. Brixton's extra tunnel space allows drivers to come in faster.
TfL operate most tube lines at more than double the current max NCL frequency but stepping up is only responsible for around 15-20% of that gap.