Andrew Heath, the CEO of POSCON, wrote a long update post on their blog regarding the development and beta of the network. Almost two months after the first beta invites went out, the team has learned a lot already and is working hard to improve communications and management. A lot of people are also confused about how the invite process works.
Pilot invites can be sent by every user who currently has access to the network. Every user can invite up to two other people. They need to be approved by POSCON staff. Members are approved whenever the team feels that they can handle it. The staff decides when they will invite new members. Asking in Discord or other channels will not get you an invite or approval quicker.
Air Traffic Controllers are obviously vital for a multiplayer network. ATC tests have been conducted regularly but ATC will still be handpicked by POSCON staff. Controllers will also have to sign NDAs. It is not always publicly announced where there will be air traffic control coverage as to not flood the airport or controller with flights. The team wants to prioritize testing features.
ATC Coverage will also be determined by POSCON staff. Some areas have better development done. ATC will be available there. The team is still working on different areas around the world. So far, 170 FIRs, 7856 ATC Sectors, 7053 VHF transceivers and 1801 independent radar sites are in the database. A few images of FIRs can be found below.
Middle Eastern FIRs 
German FIRs 
Milan FIRs 
Norwegian FIRs
Operating times will not be limited to a schedule anymore. Because server restarts are sometimes needed for new features or fixes to be implemented, the team have set up a status page which you can find here.
Heath also provides a very detailed list of what features already work, which are in development and which are planned for the future. The list can be found at the bottom of the blog post here.
