It’s a tour of Roam, but I think the way he uses tags for permanent notes is exactly how RemNote uses Concepts. If only there were a way to combine a block reference with a concept reference (hint hint [Implemented] Rem Reference Aliases).
Personally, I’m not convinced it’s worth giving up fulltext search to have absolutely everything in one program (I use hypothes.is and Memex to leave anchored annotations where I found them, though it is a bit annoying to hack together an outliner with markdown bullets. Alas, the only other option is Eloquent, which doesn’t preserve the anchors of where the highlight/annotation were taken.).