I went to the Paris one in 2016, also Hotsound Standing and the way it worked is that we went out of the room after the soundcheck and then started queuing up just outside the entrance to the venue (not outside). Then they let the Early Entry Standing in and they queued up behind us. At one point they let us in (must have been around 6pm for a concert due to start at 9pm) and it was a mad rush to the stage (they told us to go slowly but that didn't stop anyone, hehe) and I managed to get a spot on the rail dead center, barely !
I doubt any of the Early Entry Standing managed to get a spot on the rail but they would have been row 2 or 3.
At Paris 2018 the standing area was BEHIND the seated area (where I had a seat) so the people who had an Early Entry Standing I talked to (they had a little goodies bag) were not super happy as they were pretty far away and had paid more than I did for my seat I could walk to at the last minute. There were no Hotsound Standing fortunately, only first row and rows 3-6, like this year.
Hope that helps !