If lemmy created a community the same name as the username when someone signs up. You could follow a lemmy user and then when your on mastodon (once we’re federated with mastodon) you could see their self posts in their community as a mastodon post and vice versa.
We are using the standard ActivityPub protocol (with some deviations needing to be fixed). But that protocol is extremely vast, and there are many different ways to do the same thing. Its possible that implementing federation with another project might take almost as much time as implementing Lemmy-to-Lemmy federation.
Can appreciate that. From reading the other post, I got the impression that the Lemmy project doesn’t care about fediverse functionality, and I’m glad that’s not the case (?).