As said, above my head... But from my grug-brain understanding, it should only take 7-8 characters of a Nostr event ID before the chances that there is another event with the same leading characters is slim to none.

That being the case, a Nostr client doesn't really need the whole thing in order to pull up the event, so long as it is searching the right relays for it. If the full event ID is `nevent1qvzqqqqqqypzq6z80pwapdkhn6st5d5uxfm5atcl82jzyhdwmurs7q656felnj6xqy2hwumn8ghj7un9d3shjtnyv9kh2uewd9hj7qgswaehxw309ahx7um5wghx6mmd9uqzqc8ztkrnk6rnwl6dgznhtvxf6fuhpkja3y2tkuqpvl6uaxekycz5xdhvag,` then clients should only need `1qvzqqqq` to find that specific event, and those characters could be converted to mnemonic words that can be memorized or otherwise hidden in a message. Nostr clients could even support looking up the event using those mnemonic words.