Gonzo,
We beat you!
9 R/W changes during an afternoon at EGCC during the early 1980s.
Oddly enough, it was when the watch supervisor, (the late Phil Shone), had rostered the 3 most junior ATCOs on his watch, (including me), to man the VCR. An afternoon of continual and variable Cb activity resulting in a VCR Watch-Log reading...QFU24,..QFU06.....QFU24.....QFU06..and so on.
Just after tea-time, Phil came up to the tower to see what was going one on, saw the 3 a/c backtracking to the other end, and went back downstairs.
Happy days.