Is there a way to save the passphrase on the device by protecting it with a separate PIN code, instead of entering it every time you need to sign a transaction?
If none of the devices have this option now, do you plan to add it in the future?
This is not possible with any Trezor model currently, and we do not plan to implement a feature like this. The passphrase needs to be entered manually every time you want to sign a transaction.