Boost did a one-time verification with TAC. After which, further use will just be pre-authorized.

If someone tries to add your BigPay card, you will get a new TAC.

Yeap   

Anyway, just sharing my frensssss experience.
When you hit certain withdrawal limit, BigPay will call and ask for the reason why you withdraw so much, yada yada.

Ultimately, regardless what you told them(test the apps la, utilize credit card cash back la, need money from credit la, this la that la) or what they told you, what they really looking after, is your credit card statement (cc used to reload bigpay) and bank account statement (account used to deposit cash withdrawed from Bigpay) to examine the cash flow.

Most of my fren choose to surrender the info, and they got unblock.
Some choose to pattern, continue to block.