I have had 100% success with the "backup balance" feature, I sometimes just send my "brother" money using venmo, paying with the Uber debit of course!
Shortly after sending the money to my brother, Its transferred to his debit card instantly and now its liquid. Thats one way to work around the restricted banking system we have in place here. I mean cant a guy just move a few mil here and there once in a while without having suits chasing him? Go bank never nags me about keeping the balance in red for a few days or a week. No worries. Its not that bad of a tool, but as mentioned just watch out for those ATM fees.
in other parts of the world you can simply go to any banks ATM machine and instantly transfer a decent amount of money from one debit to another debit card, any bank, any atm network. Just need the 16 digit card number and an amount you want to send. Instant, Direct, and always free. I miss that system.