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In brave browser BAT you can sync settings & bookmarks saved in the browser that claims to be decentralized non custodial so how is that possible then?
I'm not a brave user, but that's up to the developer. Since Brave is their main product with an embedded wallet, it's only natural that users can do anything on their own platform including restoring user settings just by connecting their address. You should also ask, can BAT restore external wallet configurations such as metamask? No, because they are not the same product.