This is a discussion on How come ACR has such long registration periods? within the online poker forums, in the Poker Rooms section; I'm playing the 11 cent $25 GTD freezeout and it's on the bubble, but there is also 17 levels of registration remaining.
Can someone register
I definitely am not a fan of long registration periods as well for many of the same reasons listed earlier.
As for your example from earlier, I believe ACR doesn't allow that to happen. What I mean by that is if there is a big jump in paid places (for example, 108 to 180 places ITM is a common one) and if before that change happens there are less than 180 players actively playing, they will close registration early right before that jump from 108 to 180 places happens and keep it at 108 get paid.