[Google Chrome] master_preferences file question

I know there are group policies for Google Chrome, but unfortunately they are only great if you only have 1 instance of the web browser installed, otherwise they will apply to all instances of the web browser. Bummer.

I'd like to configure things like user data dir and other settings, but using the master_preferences file. The file is placed at Program Files, so only administrators can access it, which means its as secure as group policies.

I'm aware of settings like these (-http://dev.chromium.org/administrators/configuring-other-preferences), but I'm wondering if it would be possible to configure the user profile folder, etc? So far, I have found no info that could point me in the right direction.

Does anyone know if something like that would be possible? Otherwise, the fine folks over Chromium/Google could implement it.

P.S: To clarify, this Chromium/Chrome instance would not be run in a direct way, but rather through Chromium/Chrome Frame, so shortcuts are also out of the equation. I'd like to change the default profile folder to another container, but Group Policies aren't working, because they affect all other installations.

-edit-

This is really disappointing. I spent an entire afternoon searching for it, and absolutely nothing, at all. One would have thought that Google would have such settings for the master_preferences file. It just makes sense to have them. Big bummer.