No, I cannot - that's news to me!
When I was flying the VC10, there was a specific brief for VSOs who were to fly in the aircraft and the captain had to be a current QFI. The VSO would be given a brief and a short session in the simulator.
If they wanted to fly the take-off, we practised the abort scenario in the simulator. This was to a different SOP than the normal take-off; the QFI would call "ABORT - I HAVE CONTROL!" and the VSO would take hands and feet off. As the QFI, I would close the throttles (if the Air Eng hadn't already done so), extend the speedbrakes, select reverse on whichever engines were still producing thrust and start braking and steering to a halt. It was a blur of activity, but was the safer option as it would have been all too easy for the VSO to forget a crucial part of the drill.
The only questionable aspect of flying a VSO was if he wanted to do some prodding. Fine if he'd flown big aircraft before, but if not....
