I’ve had an idea, that I could easily pivot to this and become a FOSS solution. But, I wonder if it actually solves a problem. Essentially, I wanted my lemmy instance to allow sign-ups. But, the posts and channels were auto-generated. So when you log into the app or sign-up it creates a community in the instance along with it. (loom.nyc/c/pexavc) and then all the posts are automatically generated from the posts you save anywhere in the fediverse. (The app supports lemmy and mastodon for now). But, this would also allow all your bookmarks to essentially “federate”.
Edit: Tbh, it sounds like a more “silent” cross-posting