Seems like there should be a feature to offer the full Lemmy community and posts for all federated instances. This would serve a multi-node/instance backup that doesn’t rely on the users to search for posts on instances they are lurking in. The manual searching function is just not user friendly.
This should obviously be an opt-in feature so small instances are not overloaded.
Have you tried selecting “all” on the front page of your instance? I think this is the feature you are referring to anyway.
In the future, as the rules state, this community is for open-ended questions, not … suggestions for new features 🤔 honestly not sure how you managed to post it here, no worries though.