• Issue 2020 – Synchronize two local directories
  
• Issue 52 – Use file hash as criterion for synchronization
  

Exact but my SFTP will support this functionality (and more...) in the new version ;)

There is very few SFTP servers supporting MD5 (or something similar), if any at all.

In the properties for a folder, add an option for "local sync directory." Use it to do an md5sum for the respective remote and local folder being displayed, so you could show changed files with a different icon.

Of course this could also be used by the "Synchronize" option.