You just follow those users at their @user@pixelfed.social or @user@tube.jenna.net handle. Depending on the service you are using there can be caveats (I think

You just follow those users at their @user@pixelfed.social or @user@tube.jenna.net handle. Depending on the service you are using there can be caveats (I think pixelfed only tracks new content from mastodon after you follow the user) but otherwise it "just works". caveat: This only works as long as your instance hasn't de-federated those instances.