I have also worked under Code 60 in the middle of the night with a field of over 90 cars circulating and I have never felt safer.
It would have to displayed (and withdrawn and green flag displayed) simultaneously at all posts and therefore could only be used at circuits where radios and/or broadcast system is used.
The instruction is usually given 'All points display Code 60 Flag'. It is normally waved slowly initially (to draw the drivers' attention) then held stationery for the remainer of the period. (If the same size flag is used it is huge!) It is replaced by a waved green flag when it is clear to go racing again.
As others have said.................Bring It On!
I can't see it being utilised at BTCC! Can't have the gaps not being closed up to make good TV!