You would love kbin.social.

It combined posts from Lemmy and Mastodon, allowing to browse and sort both of these like on Reddit. Mastodon toots were matched to respective magazines (like Lemmy/Piefed communities) based on their hashtags. And multireddit-like feature (called Collections there, and recently reimplemented in federated form by PieFed as Feeds) allowed any user to combine several magazines, Lemmy communities and Guppe groups in a single view.

All of these has been inherited by Mbin (a /kbin fork), outside of Collections/Feeds.

Largest instances are https://fedia.io and https://kbin.earth. There are much smaller, than flagship /kbin instance have been, though, so both will be aware of less posts...