Your question has prompted me to create nostr:npub14sl07pu8rq2e3c9gz2qm3087gxn4panhmy0lsv8qtncgcuh0urrs2tpscu
We can use it to test nostr clients.
- I had success with "host not found" failover in Nostrudel and Primal.
- Removed blobs (404) did not fail over.