A Firefox feature I find myself using often is profiles because it allows for the storing of user settings, preferences and other user-related data in a user-specific location. This differs from letting the browser decide the location, which will likely use a system default.
I find this feature very useful because it allows users to manage their browser data as a package, which can offer more than, say, the Privacy tab in Settings. For example, I have some websites I need to regularly access in a private context, which can make private windows a hassle. With Firefox profiles, I'm able to store the browser data in a password-protected disk where the session is private and can be restored.
I imagine most users would opt to use a default location, but for the users interested in this, it would offer one of Firefox's standout features in Orion, which I haven't seen other browsers replicate.
When a user goes to manage their profile (whether creating a new one or modifying an existing one), there would be an option to set the folder to store the data in. After the folder has been set, Orion would use it as the folder for all data associated with a profile. This is not too different to, say, Apple's Keychain Access app, which allows users to create their own keychain and load it as a file.
The main downside I could see with this kind of feature is that, in the case Orion makes use of folders managed by the system, the user specifying their own folder may require the browser to reimplement them (say, if ~/Library/Caches was cleared in the case of low storage, which I don't believe it does). In addition, if the data were to be stored on a removable volume (say, an external storage drive), the volume being unmounted while Orion thinks it hasn't could result in unexpected behavior (in Firefox, the app just freezes). I think this would mainly be of use to a power user that could handle these hiccups, given that they have to be aware of their location.
