To avoid any confusion, are you talking about the PIN code that unlocks the physical device or the password to the Trezor Suite software?
Thank you for the clarification, yes I meant the Trezor PIN code that we need when we want to connect the wallet.
If you forget your Trezor PIN code, you can reset the device to factory settings, import your seed, and set up a new PIN. The seed + any connected passphrases are essential. Nothing else is.
Yes, your words are correct in the long run, meaning in the end he only need the SEED or the private key, because in case we forget the PIN or any other problem occurs, he can do a factory reset of the hard wallet and restore everything via the SEED as you mentioned.
Also, he can recover any coin using its private key using any other wallet in the event that the hard wallet, for example, is damaged, lost or stolen.
But what I meant is that he needs to save the Trezor PIN code for daily transactions, because when he wants to connect the wallet to any site, he needs to enter the password. The PIN is necessary for every wallet connection, so he must remember it always. This is what I meant.