Here: github.com/mastodon/mastodon/p…

the only way around this I can figure out is to periodically call the public unauthenticated timeline API methods. That would make it less realtime, and you'd probably need to keep track of which ID the last post was so you can paginate through. But definitely not ideal and I'd imagine you'd run into a lot of rate limiting for bigger servers.

and of course not to mention the resource increase... so might not be worth it at all. That's annoying.