But if you have backup second factors (you have backup second factors, right?) and you're worried about Passkey lock-in for whatever reason… just use that other second factor for AWS or any other account which supports only one.

> Now, you can add multiple MFA devices to AWS account root users and AWS Identity and Access Management (IAM) users in your AWS accounts. This helps you to raise the security bar in your accounts and limit access management to highly privileged principals, such as root users. Previously, you could only have one MFA device associated with root users or IAM users, but now you can associate up to eight MFA devices of the currently supported types with root users and IAM users.

— https://aws.amazon.com/blogs/security/you-can-now-assign-mul...