De-dupe files across users of kopia

Obviously it supports De-dupe per user but doesn’t extend further than that?

For instance we have multiple computers that many of the same photos. However each photo directory is not identical per computer. Is it possible to de-dupe these files so that only one file is used for the backup process simply referenced across multiple users of kopia?

If you are backing up to the same repository from all computers, all identical files will hash to the same value and only one instance will be stored. The others will reference the same file, even if you rename files on other computers.