Why do you *have* to use Uphold? If you have coinbase, you can swap the BAT for USDC and there are no fees to sell the USDC when you receive it in the Coinbase account.
As a publisher I have to: "Before you can redeem BAT you will have to connect your Brave Rewards account to Uphold"
Source: https://brave.com/publishers-creators-privacy/
Source: https://brave.com/publishers-creators-privacy/