Since I've been part of NPAS I've had quite a few jobs where we have requested another aircraft whilst airborne. This provides a seamless handover with ground units and control rooms and means no loss of service due to fuel. It's also very easy to do as we are all on the same radio channels.
That didn't happen before NPAS.
The guys down in the Midlands region were doing this years before NPAS came along.
It was even more "seamless" back then, because they didn't have to go via a control room and the approval process.