All of these ‘quick dash across the platform’ non-connections sound alluring in theory but tend to fall apart at the first contact with reality.
As a former Station Manager I well know that the issue is never with the fit regulars who are able to achieve it in 30 seconds. It’s the fact that another passenger hoping to make the same journey is at the far end of the arriving train, never been to Leicester, Derby or wherever before, is waiting for booked assistance to turn up with the ramp and immediately turns 30 seconds into five minutes.
Meanwhile the signal had been cleared, route locked and other movements brought to a stand.