I would recommend using the CMRA. If the IRS has issues with your tax filing, they generally contact you via the USPS. If you don't get those letters, things can get worse. I'm not really sure why you haven't been working on moving over to the CMRA. The only company I've had a problem with (using the TX service) is Bank of America. All my other financial institutions haven't had a problem. It is easy and convenient.
With regards to stimulus checks, the IRS is trying to do direct deposit as much as possible. If you did not list a bank account on the previous year's filing, you may be able to update the IRS. They claim to be building a portal. Useful info is here - https://www.irs.gov/newsroom/economic-impact-payments-what-you-need-to-know