It will do what you describe, but since you are handling large files you should know that Syncthing currently doesn't do dedupe, so if you rename or move a file

It will do what you describe, but since you are handling large files you should know that Syncthing currently doesn't do dedupe, so if you rename or move a file, or have multiple copies of it, it will sync the whole file again. Changes within a file that don't move are handled efficiently.