It's been a lot of work, but Takahē 0.6 is finally here! https://docs.jointakahe.org/en/latest/releases/0.6/
Among other features, this includes initial Mastodon Client API support (for existing client apps), custom emoji support, reporting and moderation queues, and a lot of UI and efficiency improvements.
There's still plenty more to do, but we're excited to get to a point where a new community could be run on Takahē. We'll be opening up https://takahe.social registrations soonish too!