I used google authenticator and sms verification too the phone that I am using doesn't have any apps just email and authenticator for me to prevent hacking.
That is a good idea. If affordable, use a dedicated phone for Google Authenticator and the email. The email address should be dedicated for investment accounts only.
I have a sim lock on my phone number so that it cannot be transferred to another devise unless I go to the store in person with valid IDs.