b) Unfortunately, X breaks other important things, like audio/video calls. It currently feels like an alpha-quality release: buggy and lots of missing features. Not ready for widespread use.
Someone let me know later that threads are hidden behind a Labs setting, but it only allows the client to reply to threads, but still exposes the entire thread inline for the channel which sucks up all the air in the chat.
what you are describing is the old threads workaround which predates the proper solution in labs which should exit labs asap.
Uninstalling the app, reinstalling, and making sure the labs option is turned on before navigating to a room with threads, is behaving how I expect.
So maybe, its a bug that the room does not re-render after toggling that setting.