It's the most efficient way to synchronize 2 relays. Seems like rust noatr implements it https://github.com/rust-nostr/negentropy
Discussion
then we will implement it, let me give it a look
nostr:nprofile1qqsqqqqqqqr99ezjae52qyv8lvyv3x2fdj6xedgar2sgq0gx8t8dhfcpyfmhxw309ahx7um5wf4xztttv9exjttgw368qtngv4nh2un09e3k7mf0qy88wumn8ghj7mn0wvhxcmmv9uq3gamnwvaz7tmwdaehgu3wxymrvvfwd9hj7jegwrl, if it helps, here is how I implemented it for the nostr-relay-builder: https://github.com/rust-nostr/nostr/blob/06dd1b6e532a611929278f9374aa4340455f0f54/crates/nostr-relay-builder/src/local/inner.rs#L698
👀 thanks Yuki 🤛 🤜