We have used this approach for a long time.  I first noticed Robson doing it.  Also Brooker and Buchanan, so there is some of what you describe in it.  However, where I have seen it, it's a modified version of what you describe in which the player is alone and far away, typically unmarked, as if being hidden from the opposition ready for a surprise attack.

The frustration with Wallace on the wing, as opposed to the mild comedy of Robson on the wing, was that we were a team susceptible to turnover and first phase defensive errors leading to tries.  Why place your breakdown specialist so far from the action when you have such a weakness?