I never liked allowing pilots to do things at their discretion. It implied a complete
carte blanche to the wild children of aviation
I did, however, once clear a Single Pioneer to land across runway 36 at Tengah "at his discretion" due to a strong crosswind. Nothing else was moving, he approached across a quiet Dispersal, touched down on one side of the rw and just taxied quietly to his dispersal on the other side of the rw.
I was a very naughty ATCO, but at least I kept the traffic moving