If you decide to try it, here are some interesting feature flags: "longform_notetweets_composition_without_claims_enabled" and "longform_notetweets_consumption_enabled" - allows to write/read long tweets (over 280 characters) "web_video_playback_rate_enabled" - adds setting for a playback speed in video player "tweet_awards_web_coin_purchase_enabled" - adds new menu for twitter coins (but you can't buy them yet)

There are much more feature flags and I haven't tested them all yet. Please let me know what you think!