This feature was enable in the past, but since version 1.3 the recovery key only rescues pending rewards and no earned BAT from past months, devs decided to remove the option to see your seed phrase as an implicit way to say “Even if you have your seed phrase you can not recover your eanings” and since there where users complaining that they where recovering 0 BAT, well…
For now the efforts is to use syncV2 not only to sync bookmarks and those stuff, but to also use it like a way to recorver and protect your already gain BAT.