I don't think the optionality is an issue in terms of favouring one region over the other. The problem with a quota-only discussion is that you have to start with what the number is. Without trying to be too glib, if it is 100%, then quota works. If you could tell me somewhere between zero and one hundred, then we can start to have a discussion. However, there are far too few details for a quota-only system to be able to get to a serious discussion around whether that would work.
On May 3rd, 2016. See this statement in context.