Use passphrase instead. Effectively each passphrase under your seed phrase creates a new wallet and you can have as many passphrases as you want (meaning have a small amount on your “clean” seed phrase with “zero” passphrase and put your main savings under the passphrase).
There will be no indication of the fact that you have a passphrase, so essentially you can use it as duress wallet without “duress” menu item in your hardware wallet.