Used Verifly from MEX to LHR on 12th Dec and it was seamless. Befofe the First check in there was an agent who was firmly telling people to go back to a different pop-up desk for document checking but after she saw we had Verifly green ticks, we were waved straight through to drop bags and have tickets printed. (Used the MedicSpot test to fly swabs and the Verifly manual verification took about 2 hours with no issues whatsoever)