Register Hardware Token option is always shown in the Management Portal
In 5.8.2 this configuration would hide/show the "Register a hardware token" button based on the group membership of the logged in user. After upgrading to 5.9.1 the button is always shown regardless of group membership.
It's currently not possible to hide the Hardware Token button based on the user's permissions. This has been submitted to product management for review and will be considered for possible inclusion in a future version of Defender. No release date is available at this time.