Happy to have inspired ๐ Having a real DB that juggles between memory and disk and saves the indexes sure makes sense.
I could try and see if nostr-social-graph could use indexeddb and not have to load everything into memory on app start. For native, I've made a social graph pull request to nostrdb: 
GitHub
GitHub - mmalmi/nostrdb: The unfairly fast embedded nostr database backed by lmdb
The unfairly fast embedded nostr database backed by lmdb - mmalmi/nostrdb