KNIME 4.3.3 - Change Extension Sites for global deployment

We are trying to setup a generic deployment of 4.3.3 inside the company.
We need to remove the standard internet based sites for extensions and add our own internal repo so only the internal repo is available. .

We did that and created a new workspace knime-workspace-433

We think the only way to make this change is through a workspace.

Now, we need a user to get this new workspace by default.
We updated the default path on startup and that works for the installed person but we need to pass that to a new person on installation…

Is this the best method to update these sites or is there a configuration file that we could update programmatically?.
Is there a configuration file we can update to get the new preferences file as the default