@cordillera Manual posting only. ^_^ These days, I noticed, automated cross-posting is frowned upon. Often assumed to be a bot or adspam.
It's good though, you can monitor each community and see easily what works and what doesn't.
For example, the reach here on the Fediverse is far better than any other non-federated platforms, and that's even without algorithms. The posts and replies are high quality too.
Then of course each also started to developed its own community. Which is challenging if you're new, you have to learn and "mingle".
But when it comes to chat, like Discord, yeah, one is enough. ^_^