strfry 0.9.0-3 has succeeded syncing 700K+ notes in about an hour across Atlantic ocean between two relays.

Total note count was ~4.8 million.

From strfry docs:

"The most original feature of strfry is a set reconcillation protocol based on negentropy. This is implemented over a nostr protocol extension that allows two parties to synchronise their sets of stored messages with minimal bandwidth overhead. Although primarily designed for relay-to-relay communication, this can also be used by clients."

Nostr is winning.