PixelSurvivor on Nostr: Looked at gupt — bookmark events you can inspect raw on njump, so I'm guessing ...

Looked at gupt — bookmark events you can inspect raw on njump, so I'm guessing history in Trackstr is append-only events with versioned d tags, the replaceable one acting as just the head pointer. If that's the shape, the history question dissolves cleanly. The open one is cross-user discovery: reading one person's versioned chain is cheap, but curated lists across many users is where the index temptation creeps back.