As you experienced - we are happy to quickly add people to the closed beta.
We don’t want to move to open beta until teams can easily build an entire title from start to ship. Primarily this is full binding to Unreal Engine 4 and documentation. Hopefully open beta will be in May.
The time we spent on the booth at the Game Developers Conference and more recently getting new team members up to speed has been taking more time that we would like - however things are starting to hum now.
Currently in development - the number of Unreal Engine bindings has increased from about 80 to somewhere around 5000. This is using the same system using C++ meta tagging that Blueprints use - so any commands available to Blueprints will also be available to the plug-in.