Sounds like a very good reporting system is in place at Heathrow and there must be a tremendous amount of data available to prove a safety case to ICAO.
Funnily enough in the wind conditions today, easterlies with a tailwind required an extra mile on the spacing (and wake separation) while westerlies into a strong headwind was minimum radar and wake separation.
FPOBN, the time interval between inbounds was shorter when we added an extra mile in a tailwind and longer when providing minimum separation in a headwind. So which was safer, the longer distance or the longer time interval?