The 21st of October 2024 SQLITE introduced sqlite3_rsync. 
More here: https://www.sqlite.org/rsync.html

Unfortunately, they didn't package a download for OpenBSD specifically. 
More here: https://www.sqlite.org/download.html
Is there a plan to port this? 

I don't believe I'm alone in syncing sqlite DBs to and from OpenBSD boxes. This tool allows for much more efficient and safe syncing.

Rodrigo
succulentoats.com