It's been discussed before and so far I prefer to force a sync after change and not to make it optional. The reason is that it's easy to get things wrong when it comes to sync, and when it's wrong to understand why and where it comes from, and to fix the situation.
The wise thing to do to minimise conflicts is to sync as frequently as possible. If we add an option, people will disable it, or increase the delay, and end up with conflicts or "lost" notes (just not synced) and think the app is broken.
So the current delay is more or less a feature of the sync algorithm, required to make it work properly, and it's unlikely an option will be available to change it.