The meet up before the race is the same place as last year here is a google map link to it. I think people will start meeting up from 8.30ish onwards depending on the wait at loo's and bag drop. It's just by the steps leading up to the war rooms.
Looks like this is the place for the meet up afterwards. I think it's arranged so there is no specific time so no one feels under pressure while they are running, which makes sense to me.