When Will The Next Flarum Beta Be Released?
I don't know. Nobody knows.
Now take a deep breath and wait with the rest of us while the devs work out their magic! ✨
How to know when it's there? Subscribe to releases of flarum/core using libraries.io, automatically notifying you when new releases are tagged on GitHub. You will be able to read about it on the forum and on Twitter.
How to contribute? You're in luck, here's a page on the Flarum website that covers just that!