Outbox model for known unknowns (missing notes you have the hash of) is perfect… 

…for unknown unknowns (missing notes you don’t have the hash of) can do set reconciliation using Negentropy to the relay(s) the NIP65 note specifies in an interval-based schedule (check the relay every X amount of time).

That way all 3 models are used all the time. It might be impractical to only use outbox for *all* unknown unknowns, so I lean in this direction for practicality’s sake.

If the static list is censoring, then the interval based syncing with negentropy and the NIP65 relay will get around it once the interval is reached. ⏳ 20/20 in hindsight but makes perfect sense.