I frequently run into issues because of a missing feature when editing a remote file (SFTP), therefore the priority is high. Remote files are not automatically refreshed when they change on (the remote) disk.
I'm not sure the best way to implement this, the below are suggestions only.
See also related #341 FTP: set buffer read-only flag from remote file
PS: the issue I typically see is when a colleague changed some code (in Perforce source control) in the same file where I'm working. So I have to merge the file. But it's easy to forget to hit reload in jEdit, and when you do that, your colleague is angry because you trashed all his work :(