This involves adding the CAS device to the Management Center's managed devices.
There is a requirement to create a separate "Enable" password on CAS for security purposes like creating a separate "Admin" account for the device access from the Management Center.
The CAS device is able to create multiple "Admin" accounts but can only create one "Enable" password.
On the Management Center, you still could add the CAS device using the separate "Admin" account that you created on CAS from the GUI without entering the "Enable" password but there might be some issues if the Management Center needs to run some jobs or scripts that requires CLI access. The Enable password is an option to add the CAS device on MC. However basic monitoring function will still work with just the other "Admin" account without the "Enable" password.
This is more of a limitation on the CAS device and a feature request would be required in order for creating another "Enable" password.