Most of the time, the IRS knows that you used a refund transfer bank, and will avoid using it for a deposit, and will mail you a check or debit card instead. And if the IRS does try to make a stimulus deposit to SBTP bank, the bank will try to recognize it and block it, which will also cause the IRS to mail a check. In the rare case that SBTP accepts a deposit in your name, they will contact you.
Use the IRS web site to check the status of your payment and to give the IRS your correct bank account information.
https://www.irs.gov/coronavirus/get-my-payment-frequently-asked-questions
