Any profile data that is needs to be persistent for a user is stored in %appdata%. All of the data in %localappdata% are things that are temporary (cache and things like that).

We don't currently have a way to put all profile information to a specific path, but if you modify profiles.ini to point to a specific path, all profile data will go there.

You can also start Firefox with -profile "profile_path" and it will put all profile data there. See:

https://developer.mozilla.org/en-US/docs/Mozilla/Command_Line_Options

What specific data were you seeing in a different location by setting Group Policy? It doesn't change the location of any data.

My apologies here...I was looking in the wrong place due to some folder redirection policies that I didn't think were in effect for the user I was testing with. Bookmarks data does appear to be logging to the correct location.

One oddity I found: I have a GPO set up to configure a default home page and disable automatic updates, and I have verified registry keys were created as expected under HKLM\SOFTWARE\Policies\Mozilla\Firefox. To test, I removed all Mozilla directories under %appdata% and %localappdata% and restarted Firefox. The first time Firefox starts does not get the default home page I configured. Subsequent restarts of the Firefox browser brought up the desired home page as expected.

Thank you for your time. Again, apologies for not paying closer attention to this issue.

I'm wondering if you're actually seeing the first run page (which we use as the homepage).

Try setting this value to empty:

https://github.com/mozilla/policy-templates/blob/master/README.md#overridefirstrunpage

That indeed was it. I missed that particular setting when configuring the GPO the first time.

Thank you for your time!