JFK did it on the two flights I heard last night. The time between group 0 and group 1 is about 2 seconds so you need to be ready and waiting. However for long haul, I’m fine with boarding last as there’s always enough overhead space in J and F.

Last night I had to ditch the Chelsea lounge early as it was 25C in there, so did make use of group 0. I could hear the cabin crew saying “here they come” as I was the first person to get on.