Vault restart and key storage on disk

If you set vault timeout to Never, it stores the master password key on local storage. You get a warning when you do that.

If you uncheck the option of “lock with master password on browser restart”, it will allow you to use the PIN instead of master password. How does that work? Doesn’t it also save the master password key to disk like setting timeout to never? The only exception is that you have to enter a pin to unlock?

Where does it store the item. I am using this on Chrome OS, so there is no client program like in Windows. The info appears to be stored in Browser.local storage. However in windows, does the storage change to windows location when the windows client is involved?

The documentation does clearly state where the storage is store but I am not entirely clear if you using windows client with a chrome web extension, where does the vault and other info get store?