Hello. Just to explain the question, would it be possible to have a "double encryption" system in place for decrypting your drives. I will attach a diagram I made to explain further. Feel free to audit.

1. First boot partition. This would be stored in an unencrypted format and would serve as the first layer of security for the system. This then decrypts the attached USB storage device which contains the actual decryption prompt.
2. Encrypted boot USB. This would be decrypted by the unencrypted "boot" drive. After the decryption process there is another prompt for a password which would decrypt the key check portion of the security.
3. Key check. This checks security keys to ensure there is no tampering. This then decrypts your main drive to allow you into the OS.

Just wondering if this would be possible. Defiantly need some more input from others.
(im aware this is overkill schizo behavior lol)