Does anyone know if EES is being used at St Pancras for Eurostar?
I don't know but it was definitely being used the other way round at Gare du Nord 10 days ago.
Yes, it has been active at St. Pancras.
Currently, the system is still in rollout mode, they are not required to run 100% of passengers through EES, though they are supposed to be hitting targets of % volume of traffic through.
Was not in use Wednesday when I went through immigration there