How to configure owncloud to upload file conflicts

I have noticed that by default, if two users edit and save a file simultaniously, the last user to save their changes will be left with a local copy of the file that contains their conflicting changes.

I also noticed that there is no notification of this for the user, when working with the desktop client, other than a message in the desktop client itself (But there is no popup for the user).

As such I feel like an issue could arise where two users edit a file, one user has changes that are left on the local computer and not syncronised with the server.

If that computer is then reloaded for whatever reason, the local conflict file would be lost.

I have read there is an environment variable that allows the conflicting files to be uploaded to the server and I would like to impliment this, ref - Conflicts in Files

However, I cannot find any documentation on exactly where this environment variable should be placed.

Can someone help?

Edit: Just to clarify, I am dealing with a shared folder, hence why multiple accounts have access to the same files. The way I have set this up is by adding several folders to one account in owncloud, then sharing those folders with other users, effectively making a shared file system.

I have experience in the past of conflicts whereby users have been coincidently editing the same file at the same time and I would just like to ensure that if this does happen, both copies of the file are uploaded just to avoid data loss.